LanguageClient: Avoid problems with old settings

Empty file pattern entries may end up in a match everything
state, so remove them if they are still present inside old
settings.

Change-Id: Ic388522aa152265b5d10a9e334acd3e7b7032be7
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/languageclient/languageclientsettings.cpp

@@ -530,6 +530,7 @@ void BaseSettings::fromMap(const QVariantMap &map)
         map.value(startupBehaviorKey, BaseSettings::RequiresFile).toInt());
     m_languageFilter.mimeTypes = map[mimeTypeKey].toStringList();
     m_languageFilter.filePattern = map[filePatternKey].toStringList();
+    m_languageFilter.filePattern.removeAll({}); // remove empty entries
 }
 
 static LanguageClientSettingsPage &settingsPage()