LanguageClient: Reset maximum restart tries on explicit restart

If the user forces the language client to restart for whatever reason
the client may end up in not starting anymore depending on the
number of restarts that had been done already.
So, explicitly reset the counter in case the user triggers the
restart.

Change-Id: Ie5f33c8dc3d565b6126badc9708906fc14f4e743
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/languageclient/languageclientmanager.cpp

@@ -159,6 +159,7 @@ void LanguageClientManager::clientFinished(Client *client)
     QTC_ASSERT(managerInstance, return);
 
     if (managerInstance->m_restartingClients.remove(client)) {
+        client->resetRestartCounter();
         client->reset();
         client->start();
         return;