qmlls: be invalid if no qmlls was found

Make the qmlls client invalid if it can't find the latest qmlls version
(if there is no qmlls version installed for example).

Task-number: QTCREATORBUG-31897
Change-Id: I74fa72bd2a95126a2a091f88c64dfa60155e4508
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/qmljseditor/qmllsclientsettings.cpp

@@ -163,6 +163,9 @@ bool QmllsClientSettings::isValidOnProject(ProjectExplorer::Project *project) co
         return false;
     }
 
+    if (m_useLatestQmlls && evaluateLatestQmlls().first.isEmpty())
+        return false;
+
     return true;
 }