fix: do not skip po file generation on missing sources
Previously, when some po files were missing, the django.po or
djangojs.po were not generated at all. This was very inconvenient for
some languages (e.g: 'ro') that do not pass the 3% bar of reviewed
strings in some files. Here, we make a change where the remaining po
files are merged to produce the merged.po files.
This fixes an issue that occurs when we generate translation strings for the Romanian language in Tutor. See conversation here: https://discuss.overhang.io/t/translate-tutor-in-other-language/1078
This is ready to review.
can you take care of it?