Use unicode option when replacing non-words

Fixes #513

src/context/contextalbumsmodel.cpp

@@ -367,7 +367,7 @@ QString ContextAlbumsModel::SortText(QString text) {
   else {
     text = text.toLower();
   }
-  text = text.remove(QRegularExpression("[^\\w ]"));
+  text = text.remove(QRegularExpression("[^\\w ]", QRegularExpression::UseUnicodePropertiesOption));
 
   return text;