Add missing newline in fallback debug output.

This is hit in case of a recursion in the message handler, and message
hasn't gone through qMessageFormatString at this point and thus lacks
the newline.

Change-Id: Ia098b6ccbcc1aff22a4695865f39143ba0152d9c
Reviewed-by: Kai Koehne <kai.koehne@theqtcompany.com>

src/corelib/global/qlogging.cpp

@@ -1329,7 +1329,7 @@ static void qt_message_print(QtMsgType msgType, const QMessageLogContext &contex
         }
         ungrabMessageHandler();
     } else {
-        fprintf(stderr, "%s", message.toLocal8Bit().constData());
+        fprintf(stderr, "%s\n", message.toLocal8Bit().constData());
     }
 }