git_ui: Fix stale loading message in git history pane (#58133)

If for some reason we do not manage to find any shas, we were showing an
incorrect loading message before despite not being in a loading state
anymore.

Release Notes:

- N/A or Added/Fixed/Improved ...
0711d9e42bLukas Wirth committed on 6/1/2026, 6:03:13 AM· committed by GitHubparent8982fb1
1 file changedLine totals unavailable