Merge pull request #169 in CASA/casa6 from CAS-11893 to master
* commit 'b041ede38d110a197a6affc9a944c09acc0b7b4f':
Update plotms wheel
update build.conf
Set next plotms branch wheel
If doing observed data always create output sigma spectrum
Revert commit which implements wrong solution
Update build.conf
Remove debug output
Do not divide by weightSpectrum or sigmaSpectrum if the do not exist.