LanguageClient: Sync settings on plugin initialization

Otherwise we might end up starting a second language server
when opening options page of Language Client plugin and
closing again with 'Ok' without modifying any setting.

Change-Id: I2b16436b92a0d622dc7df1b5fbdaf9f9f8e717a2
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/languageclient/languageclientsettings.cpp

@@ -216,6 +216,7 @@ void LanguageClientSettingsPage::init()
 {
     m_model.reset(LanguageClientSettings::fromSettings(Core::ICore::settings()));
     apply();
+    finish();
 }
 
 QWidget *LanguageClientSettingsPage::widget()