Steps to reproduce:
* Begin importing https://de.wikipedia.org/wiki/Datei:GermanyDemRepPFX1-50Pfennig-1979-donatedmjd_b.jpg
* Type something into the edit summary
* Click "Import"
* You are presented with a title change dialog. Continue without changing anything.
* You are returned to the import preview, but the summary is blanked.
At this point, if you populate the summary again you'll be sent to the title change dialog a second time, and this loop will repeat if the same steps are taken. Leaving the edit summary blank allows "Import" to actually import.
 When a file's name is automatically changed to the accurate file ending (e.g. it was called "png", but it is actually "jpeg", and thus we changed it), this has no effect on any other part of the interaction.
 Specifically, the edit summary should stay intact, be changable, and no import should be blocked.
- This should probably contain a regression test