Apply changes of global tab settings to editors

Return global tab settings in case there are no
code style settings for passed languageId

Task-number: QTCREATORBUG-6429
Change-Id: Ieccd265fa03bfba0832d285a6443633dd27ba03a
Reviewed-by: Leandro Melo <leandro.melo@nokia.com>

src/plugins/texteditor/texteditorsettings.cpp

@@ -368,7 +368,7 @@ ICodeStylePreferences *TextEditorSettings::codeStyle() const
 
 ICodeStylePreferences *TextEditorSettings::codeStyle(const QString &languageId) const
 {
-    return m_d->m_languageToCodeStyle.value(languageId);
+    return m_d->m_languageToCodeStyle.value(languageId, codeStyle());
 }
 
 QMap<QString, ICodeStylePreferences *> TextEditorSettings::codeStyles() const