Fix handling of translations with context
Fix handling of translations with context

Without this fix, just one of the translations with the same original string but different context would be included in the generated mo data

oscarotero/Gettext,PSF1/Gettext,PSF1/Gettext,hnq90/Gettext,icebird93/Gettext,icebird93/Gettext,oscarotero/Gettext,hnq90/Gettext