LanguageClient: request link from active server for the document

Instead of sending the link request to all reachable server send it only
to the server that is currently used to handle this document.

Change-Id: I27a8d0e4573f734baa2931a0af771e60665a4532
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/languageclient/languageclientmanager.cpp

@@ -503,9 +503,9 @@ void LanguageClientManager::findLinkAt(TextEditor::TextDocument *document,
             }
         }
     });
-    for (Client *interface : reachableClients()) {
-        if (interface->findLinkAt(request))
-            m_exclusiveRequests[request.id()] << interface;
+    if (Client *client = clientForUri(uri)) {
+        if (client->reachable())
+            client->findLinkAt(request);
     }
 }