gnupg2: add option to symlink 'gpg' to 'gpg2'
gnupg2: add option to symlink 'gpg' to 'gpg2'

So it turns out this is a better way to get bin/gpg, as the
program-transform-name option apparently doesn't touch everything and
results in some functional breakage.

Signed-off-by: Jack Nagel <43386ce32af96f5c56f2a88e458cb94cebee3751@gmail.com>

DomT4/homebrew-versions,heuermh/homebrew-versions,jimhe/homebrew-versions,UniqMartin/homebrew-versions,Ashton-W/homebrew-versions,coeligena/homebrew-verscustomized