[Cashtab] Reply To Message button should just read Replyr

Summary: Related to T2502. Reply To Message button has been changed to Reply.

Test Plan:
cd web/cashtab && npm start
If there are no message Txs in recent history, receive a message Tx
Observe that the Reply To Message button now reads 'Reply'

Reviewers: bytesofman, #bitcoin_abc

Reviewed By: bytesofman, #bitcoin_abc

Differential Revision: https://reviews.bitcoinabc.org/D11638