[Server] Clean up logAppend and add new message for server shutdown

apps/openmw-mp/Script/LuaState.cpp

@@ -139,7 +139,7 @@ LuaState::LuaState()
         LOG_MESSAGE_SIMPLE(level, "[Script]: %s", message);
     });
     lua->set_function("logAppend", [](unsigned short level, const char *message) {
-        LOG_APPEND(level, "[Script]: %s", message);
+        LOG_APPEND(level, "%s", message);
     });
 
     lua->set_function("stopServer", [](int code) {

apps/openmw-mp/main.cpp

@@ -314,6 +314,8 @@ int main(int argc, char *argv[])
 
     if (code == 0)
         LOG_MESSAGE_SIMPLE(Log::LOG_INFO, "Quitting peacefully.");
+    else if (code == 1)
+        LOG_MESSAGE_SIMPLE(Log::LOG_ERROR, "Forcibly shutting down because of error.");
 
     LOG_QUIT();