Regenerate out-of-date translation strings

Summary: The base translation file (bitcoin_en.ts) hasn't been updated in some time.

Test Plan:
cd build/src
make translate
bitcoin-qt (I tried another language, but the vast majority of strings are currently untranslated; English still looks ok as expected)

Reviewers: deadalnix, Fabien, #bitcoin_abc

Reviewed By: deadalnix, #bitcoin_abc

Subscribers: teamcity, schancel

Maniphest Tasks: T9

Differential Revision: https://reviews.bitcoinabc.org/D2662