runners/recentdocuments: Fix results being discarded when casing is different
BUG: 474782 Regression from ecfc27c2
Test Plan:
- Create a file called MyTextFile.txt
- Open it in any KDE app so it is in the recent files list
- "MyTextFile" should work as before and provide the result
- "textfile" as a query should only provide a result with this change