Fixup find_missing_translations.js (#2637)
Fixup find_missing_translations.js (#2637)

Remove auto-generated files from consideration, and fix a bug where
text blocks including variables were not considered.

Fixes #2608
quisquous/cactbot,quisquous/cactbot,quisquous/cactbot,quisquous/cactbot,quisquous/cactbot,quisquous/cactbot