Previously /cancel was intercepted inside the 'unknown' branch, and the
comparison used the command WITHOUT the leading slash while parseCommand
returns it WITH one ('/cancel') — the check never matched, so /cancel
always fell through to the unknown-command reply, even with a pending
ask/approval.
Now a first-class command (menu included): closes the TG-side
answer/approval channel when one is pending, otherwise reports that
nothing is awaiting a reply.
RRRosmontis
cecb655a4b