MFH: r526173

Unbreak. The port had been broken while fetchmail 6.3.26 had
been removed by upstream and before mail/fetchmail had been
updated to 6.4.x - it fetches properly.

Regarding Python 3.x compatibility,
see: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=244130

While here, fix TARGET -> ALL_TARGET to avoid building the C stuff,
and drop the unused obsolete distinfo file.

Approved by: ports-secteam (blanket, unbreaking broken port)