gpg: Disable an MD5 workaround for pgp2 by default.
* g10/sig-check.c (do_check): Move some code to ... * g10/misc.c (print_md5_rejected_note): new function. * g10/mainproc.c (proc_tree, proc_plaintext): Enable MD5 workaround only if option --allow-weak-digest-algos is used.