Changing systemlang to an unrecognized string causes CS to not start up.

Setting the systemlang in Columnstore.xml to an unrecognized string will cause the system to not start due to an uncaught exception crashing WorkerNode. In utils/funcexp/utilsutf8..h, idb_setlocale() attempts to set the C++ locale with the return value from setlocale(). If setlocale() fails, which it will with a bad string, then the c++ locale is set with a NULL string, which throws. We need to do the c++ locale after we test for NULL.