[Epix100][Correct] Calcat error when no gain retrieved
Description
Fix a bug for epix100 correction notebook to avoid CalCatError when the relative gain is not retrieved. The bug was faced when putting back the MID_EXP_EPIX-1 test.
The fix is doing the same as how we handle retrieving dark and gain constants for AGIPD correction.
How Has This Been Tested?
Relevant Documents (optional)
Types of changes
- Bug fix (non-breaking change which fixes an issue)
