Minor bug correction

[jmilou]

I noticed a minor bug, without noticeable consequences in the various tests I did to investigate the impact on a scattered light image. This PR corrects the bug.

[VChristiaens]

Hi @jmilou, thanks for noticing the bug. The PR doesn't seem to pass the automated tests associated to the scattered light disk module. Do the tests need to be updated too?

[jmilou]

Indeed, thanks for pointing me to this problem. I forgot to update the automated tests associated to the scattered light disk module. This should now work.

[VChristiaens]

Thanks @jmilou. Since the pushed changes regarding the tests can't be applied immediately, I'll accept the PR even if the (previous) tests do not pass. Maybe worth checking soon on your side that the new tests do run smoothly, e.g. with a dummy push with the new version.

[VChristiaens]

@jmilou Update on my side: after a new dummy push including your changes, most tests appear to pass now, except one. Below is the short summary re: the failed test. Could you please have a look? Thanks!

FAILED tests/test_fm_scatteredlightdisk.py::test_HG_phase_function_and_print[0.4] - AssertionError:
Not equal to tolerance rtol=1e-05, atol=1e-06

Mismatched elements: 1 / 1 (100%)
Max absolute difference: 0.16698601
Max relative difference: 13.37172119
x: array(0.179474)
y: array(0.012488)