don't open database in connection pools if main database connection is not valid

servatrice/src/servatrice_database_interface.cpp

@@ -22,8 +22,10 @@ Servatrice_DatabaseInterface::~Servatrice_DatabaseInterface()
 
 void Servatrice_DatabaseInterface::initDatabase(const QSqlDatabase &_sqlDatabase)
 {
+	if (_sqlDatabase.isValid()) {
 		sqlDatabase = QSqlDatabase::cloneDatabase(_sqlDatabase, "pool_" + QString::number(instanceId));
 		openDatabase();
+	}
 }
 
 void Servatrice_DatabaseInterface::initDatabase(const QString &type, const QString &hostName, const QString &databaseName, const QString &userName, const QString &password)