fix: non-void function does not return a value in all control paths.

Signed-off-by: Camila Ayres <hello@camilasan.com>

src/gui/application.cpp

@@ -564,6 +564,8 @@ bool Application::setupConfigFolderFromLegacyLocation(const QString &legacyLocat
         return QFile::link(confDir, legacyDir);
 #endif
     }
+
+    return false;
 }
 
 AccountManager::AccountsRestoreResult Application::restoreLegacyAccount()