UI strings missing on Transifex

[marcriera]

Since #654 was merged, I have noticed that some parts of the user interface have missing translations when they were translated before. This is the case for the strings "F" and "B" used for power and brake notches (which become "P1", "P2", etc.).

After checking if the strings were untranslated on Transifex for some reason, I have noticed these strings (and probably many others) are missing there. There's probably an importation issue, because the strings seem to be in the updated XLF files, just with no target element.

[leezer3]

I'm sure there was a quirk mentioned in another issue about duplicate keys in the XLF or something meaning that Transifex didnt find them, but I can't find it at the minute.

@s520 I'm sure this quirk mentioned was you if you're not busy??