The gpg --verify usage example within the 'gpg.program' variable
reference provides an incorrect example of the gpg --verify command
arguments.
The command argument order, when providing both a detached signature
and data, should be signature first and data second:
https://gnupg.org/documentation/manuals/gnupg/Operational-GPG-Commands.html
Signed-off-by: Robert Morgan <robert.thomas.morgan@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>