Fix flickering in debug panel

This flickering made debug panel unusable, because most of the time
panel was white. This problem effects wxPython with GTK3+ backend
(at least on GNU/Linux systems).

Removed code IIUC draws box with content of moved debug variable, I
don't see any effect of it neither on GNU/Linux nor on Windows. It
should be safe to remove.

# pylint: disable=undefined-variable

from __future__ import absolute_import
from svgui.pyjs.jsonrpc.jsonrpc import JSONRPCServiceBase


class JSONRPCService(JSONRPCServiceBase):

    def serve(self):
        return self.process(request.body.read())

    def __call__(self, func):
        self.methods[func.__name__] = func
        return func