LanguageClient: clear running progress when resetting client

Otherwise we will have dangling progress bars after a crashed server was
restarted.

Change-Id: I889d201d7cf196623978638db67397203a8f4564
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/languageclient/client.cpp

@@ -1019,6 +1019,7 @@ bool Client::reset()
     m_runningAssistProcessors.clear();
     qDeleteAll(m_documentHighlightsTimer);
     m_documentHighlightsTimer.clear();
+    m_progressManager.reset();
     return true;
 }