moved the function of checking the availability of wireguard config to ipc client

ipc/ipcserver.cpp

@@ -3,6 +3,7 @@
 #include <QObject>
 #include <QDateTime>
 #include <QLocalSocket>
+#include <QFileInfo>
 
 #include "router.h"
 #include "logger.h"
@@ -169,3 +170,8 @@ bool IpcServer::isWireguardRunning()
     return false;
 #endif
 }
+
+bool IpcServer::isWireguardConfigExists(const QString &configPath)
+{
+    return QFileInfo::exists(configPath);
+}