leave revision 0 line in Portfile

[Mojca Miklavec]

Dear Ken,

On Sat, 22 Dec 2018 at 16:49, Ken Cunningham wrote:
>
> I would like to propose we stop asking people to remove the "revision 0" line in Portfiles.

I totally agree.

I mean:
- if users submit a PR with "revision 0", we should not ask them to
remove that line
- if users submit a PR with revision removed, we should not ask them
to add it back either (at least not until we add that line to all
other ports for some well-grounded reasons)
- if users forget to change "revision 99" after version increase, we
should still ask them to either remove it or change it to 0

> So how about we embrace the "0" and move on to stuff that matters more!!!

+1

Mojca