LanguageClient: improve Server startup

Starting a client does not need to be done via
LanguageClientManager::startClient anymore but can be done via
Client::start()

Change-Id: I571e96b6ad7d64786a345edf5dbb38208b9a1d12
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/languageclient/client.cpp

@@ -861,9 +861,12 @@ QList<Diagnostic> Client::diagnosticsAt(const DocumentUri &uri, const QTextCurso
     return m_diagnosticManager.diagnosticsAt(uri, cursor);
 }
 
-bool Client::start()
+void Client::start()
 {
-    return m_clientInterface->start();
+    if (m_clientInterface->start())
+        LanguageClientManager::clientStarted(this);
+    else
+        LanguageClientManager::clientFinished(this);
 }
 
 bool Client::reset()