fix bug in stackfitting routine

[dirkscholte]

Bug fix for the stackfit routine.

[dirkscholte]

Oh yikes... that doesn't look good

[github-actions[bot]]

Pull Request Test Coverage Report for Build 6188075234

• 0 of 2 (0.0%) changed or added relevant lines in 1 file are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage decreased (-0.04%) to 59.218%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
py/fastspecfit/continuum.py	0	2	0.0%
<!--	Total:	0	2	0.0%	-->

Files with Coverage Reduction	New Missed Lines	%
py/fastspecfit/emlines.py	1	49.93%
<!--	Total:	1		-->

Totals
Change from base Build 6187778450:	-0.04%
Covered Lines:	2470
Relevant Lines:	4171

---

💛 - Coveralls

[moustakas]

Awesome, @dirkscholte, thank you! If you could just update the change log and then feel free to self-merge once tests pass again-- https://github.com/desihub/fastspecfit/blob/main/doc/changes.rst

[dirkscholte]

@moustakas Aarrghh updated the change log from the link into the main branch! Today is not my day!