fix issue, when structure data type with array field is created

Traceback (most recent call last):
File "editors/DataTypeEditor.py", line 669, in ElementArrayTypeFunction
self.RefreshTypeInfos()
File "editors/DataTypeEditor.py", line 761, in RefreshTypeInfos
self.Controler.SetDataTypeInfos(self.TagName, infos)
File "PLCControler.py", line 2075, in SetDataTypeInfos
array.baseType.setcontent(PLCOpenParser.CreateElement(
AttributeError: 'lxml.etree._Element' object has no attribute 'setcontent'

from ..toolchain_gcc import toolchain_gcc

class Linux_target(toolchain_gcc):
    dlopen_prefix = "./"
    extension = ".so"
    def getBuilderCFLAGS(self):
        return toolchain_gcc.getBuilderCFLAGS(self) + ["-fPIC"]
    def getBuilderLDFLAGS(self):
        return toolchain_gcc.getBuilderLDFLAGS(self) + ["-shared", "-lrt"]