Fix python2 build of pyuno with older py2 versions

SyntaxError: ('invalid syntax', ('//usr/lib64/libreoffice/program//uno.py',
368, 77, "            return _ConstantGroup({c.Name.split('.')[-1]:
c.ConstantValue for c in td.Constants})\n"))

Change-Id: Ie87c21fbfd83fc4d6f918eb55128db235c2220a8
Reviewed-on: https://gerrit.libreoffice.org/22863Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>

pyuno/source/module/uno.py

@@ -361,7 +361,10 @@ def _impl_getConstantGroupByName( module, group ):
     qualifiedName = module + '.' + group
     for td in tde:
         if td.Name == qualifiedName:
-            return _ConstantGroup({c.Name.split('.')[-1]: c.ConstantValue for c in td.Constants})
+            return_dict = dict()
+            for c in td.Constants:
+                return_dict.update({c.Name.split('.')[-1]: c.ConstantValue})
+            return _ConstantGroup(return_dict)
     else:
         raise ValueError