fixes in mod Assembly for python3

src/Mod/Assembly/App/AppAssembly.cpp

@@ -57,7 +57,16 @@ void AssemblyExport initAssembly()
         PyErr_SetString(PyExc_ImportError, e.what());
         return;
     }
+#if PY_MAJOR_VERSION >= 3
+    static struct PyModuleDef AssemblyAPIDef = {
+        PyModuleDef_HEAD_INIT,
+        "Assembly", module_Assembly_doc, -1, Assembly_methods,
+        NULL, NULL, NULL, NULL
+    };
+    PyModule_Create(&AssemblyAPIDef);
+#else
     Py_InitModule3("Assembly", Assembly_methods, module_Assembly_doc);   /* mod name, table ptr */
+#endif
     Base::Console().Log("Loading Assembly module... done\n");