Patch ComTypes with a small fix

The fix is obtained from here: enthought/comtypes@7d66f3e
However we can't use that repository since it contains Python 2 code.

Contributes to issue CURA-3823.

projects/python-comtypes.cmake

@@ -2,6 +2,7 @@ if(BUILD_OS_WINDOWS)
     ExternalProject_Add(PythonComtypes
         URL https://pypi.python.org/packages/85/11/722b9ce6725bf8160bd8aca68b1e61bd9db422ab12dae28daa7defab2cdc/comtypes-1.1.3-2.zip
         URL_MD5 4161cb8bc283a75af85e220ad662d5af
+        PATCH_COMMAND patch comtypes/__init__.py ${CMAKE_SOURCE_DIR}/cmake/python-comtypes.patch
         CONFIGURE_COMMAND ""
         BUILD_COMMAND ${PYTHON_EXECUTABLE} setup.py build
         INSTALL_COMMAND ${PYTHON_EXECUTABLE} setup.py install --single-version-externally-managed --record=comtypes-install.log

projects/python-comtypes.patch

@@ -0,0 +1,15 @@
+--- __init__.py	2017-08-11 14:40:35.464581556 +0200
++++ __init__2.py	2017-08-11 14:40:47.677067679 +0200
+@@ -655,8 +655,10 @@
+             rescode = func(self_, *args, **kw)
+             # If there is only a single output value, then do not expect it to
+             # be iterable.
+-            if len(outargs) == 1:  # rescode is not iterable
+-                return rescode.__ctypes_from_outparam__()
++            if outnum == 1:  # rescode is not iterable
++                if len(outargs) == 1:
++                    rescode = rescode.__ctypes_from_outparam__()
++                return rescode
+
+             rescode = list(rescode)
+             for outnum, o in outargs.items():