When change the rank order for an type like application/rtf and move a application to top (e.g. LibreOffice Writer) instead of KWord and press "Apply" this results in a dialog with progress bar and never ends.

Reproducible: Always

Steps to Reproduce:
1. select a type, e.g. application/rtf 
2. go to general tab
3. move an application from middle or bottom to top
4. press "Apply"
Actual Results:  
Progress dialog shows up, progress changes from 0% to 100% in 5% steps, then  back to 0% and again. If you cancel this, the change will not made.
One interesting thing: If you wait long enough (some minutes), progress change stops (dialog still showing up). If you cancel in this state, the change seems made

Expected Results:  
progress dialog shows up and closes after the change is done (normally 1-10 seconds)