Fix a fr_FR typo in address selection dialog

Summary: Button label is "Coisir" instead of "Choisir"

Test Plan:
Start bitcoin-qt with fr_FR language selected
Go to "Envoyer", then clic the address book icon next to the "Payer à"
input.
Check the button label is display correctly.

Reviewers: deadalnix, #bitcoin_abc

Reviewed By: deadalnix, #bitcoin_abc

Subscribers: teamcity, schancel

Differential Revision: https://reviews.bitcoinabc.org/D2438