PL/Python: Improve error messages

Author: petere

src/pl/plpython/plpy_plpymodule.c

@@ -174,10 +174,10 @@ PLy_init_plpy(void)
 	main_dict = PyModule_GetDict(main_mod);
 	plpy_mod = PyImport_AddModule("plpy");
 	if (plpy_mod == NULL)
-		PLy_elog(ERROR, "could not initialize plpy");
+		PLy_elog(ERROR, "could not import \"plpy\" module");
 	PyDict_SetItemString(main_dict, "plpy", plpy_mod);
 	if (PyErr_Occurred())
-		PLy_elog(ERROR, "could not initialize plpy");
+		PLy_elog(ERROR, "could not import \"plpy\" module");
 }
 
 static void