Fix crash if LD input contact isn't connected

Traceback (most recent call last):
File "/home/developer/WorkData/PLC/beremiz/beremiz/BeremizIDE.py", line 339, in OnMethod
obj.CTR.CallMethod('_'+meth)
File "/home/developer/WorkData/PLC/beremiz/beremiz/ProjectController.py", line 1996, in CallMethod
getattr(self, method)()
File "/home/developer/WorkData/PLC/beremiz/beremiz/ProjectController.py", line 1134, in _Build
IECGenRes = self._Generate_SoftPLC()
File "/home/developer/WorkData/PLC/beremiz/beremiz/ProjectController.py", line 746, in _Generate_SoftPLC
if self._Generate_PLC_ST():
File "/home/developer/WorkData/PLC/beremiz/beremiz/ProjectController.py", line 763, in _Generate_PLC_ST
self._getIECgeneratedcodepath())
File "/home/developer/WorkData/PLC/beremiz/beremiz/PLCControler.py", line 456, in GenerateProgram
self.ProgramChunks = GenerateCurrentProgram(self, self.Project, errors, warnings)
File "/home/developer/WorkData/PLC/beremiz/beremiz/PLCGenerator.py", line 1762, in GenerateCurrentProgram
generator.GenerateProgram()
File "/home/developer/WorkData/PLC/beremiz/beremiz/PLCGenerator.py", line 478, in GenerateProgram
self.GeneratePouProgram(pou_name)
File "/home/developer/WorkData/PLC/beremiz/beremiz/PLCGenerator.py", line 260, in GeneratePouProgram
program = pou_program.GenerateProgram(pou)
File "/home/developer/WorkData/PLC/beremiz/beremiz/PLCGenerator.py", line 1718, in GenerateProgram
self.ComputeProgram(pou)
File "/home/developer/WorkData/PLC/beremiz/beremiz/PLCGenerator.py", line 1028, in ComputeProgram
self.GenerateBlock(instance, block_infos, body, None)
File "/home/developer/WorkData/PLC/beremiz/beremiz/PLCGenerator.py", line 1144, in GenerateBlock
expression = self.ComputeExpression(body, connections, executionOrderId > 0)
File "/home/developer/WorkData/PLC/beremiz/beremiz/PLCGenerator.py", line 1373, in ComputeExpression
paths = self.GeneratePaths(connections, body, order, to_inout)
File "/home/developer/WorkData/PLC/beremiz/beremiz/PLCGenerator.py", line 1344, in GeneratePaths
elif isinstance(result[0], list):
IndexError: list index out of range


Close #70

# SOME DESCRIPTIVE TITLE.
# Copyright (C) is 21st century inquisition
# This file is distributed under the same license as the Beremiz package.
# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR.
#
#, fuzzy
msgid ""
msgstr ""
"Project-Id-Version: Beremiz 1.1\n"
"Report-Msgid-Bugs-To: \n"
"POT-Creation-Date: 2012-09-08 01:47\n"
"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
"Language-Team: LANGUAGE <LL@li.org>\n"
"Language: \n"
"MIME-Version: 1.0\n"
"Content-Type: text/plain; charset=UTF-8\n"
"Content-Transfer-Encoding: 8bit\n"

# 175ab223adbc42749a504a6f9718fb71
#: ../../standards.rst:2
msgid "IEC 61131-3"
msgstr ""

# c2d98f5b3a4c4f6fa6fdab3b7d419f28
#: ../../standards.rst:4
msgid ""
"IEC-61131 is a normative document provided by the standards organization IEC "
"(International Electrotechnical Commission) and describing a standard for "
"implementing programmable controllers."
msgstr ""

# da7a80107e094184af3a7d6504a3718b
#: ../../standards.rst:9
msgid ""
"The part 3 of this document (commonly named IEC 61131-3) specifies syntax "
"and semantics for programming language for programmable controllers. Beremiz "
"implements all the languages described in this document."
msgstr ""

# 98082fb5f0564eb38341fd5865f3cef6
#: ../../standards.rst:14
msgid "http://www.iec.eu"
msgstr ""

# fb0bef609e7b43079133dc137afbdc34
#: ../../standards.rst:17
msgid "PLCopen TC6"
msgstr ""

# abf4b2a73aa54caba919975385b1b2af
#: ../../standards.rst:19
msgid ""
"PLCopen is a vendor- and product-independent worldwide association defining "
"international standards for various topics related to control programming. "
"For this purpose, PLCopen has 6 technical committees."
msgstr ""

# aa4df8a9f69749cdb44143a2f6a973e2
#: ../../standards.rst:24
msgid ""
"The goal of the sixth committee (TC6) is to define a standard file format, "
"based on XML, for exchanging programmables controllers programmed using IEC "
"61131-3 languages. Beremiz uses this file format for saving the PLC programs "
"of projects."
msgstr ""

# 3c0fd475a8374f8d843d142081bdaf35
#: ../../standards.rst:30
msgid "http://www.plcopen.org"
msgstr ""