Allow multiple instances when debugging (#651)

src/main.cpp

@@ -57,10 +57,12 @@ int main(int argc, char** argv)
     // don't set organizationName as that changes the return value of
     // QStandardPaths::writableLocation(QDesktopServices::DataLocation)
 
+#ifndef QT_DEBUG
     if (app.isAlreadyRunning()) {
         qWarning() << QCoreApplication::translate("Main", "Another instance of KeePassXC is already running.").toUtf8().constData();
         return 0;
     }
+#endif
 
     QApplication::setQuitOnLastWindowClosed(false);