Minor policy change for gnuradio.org

I have had to limit the ability to post new issues and comments on
issues to only those people on gnuradio.org that are members of the GNU
Radio project.

This was done to remove spamming on the issues page.

What this means. When you sign up for an account on our Redmine server,
receive an email to confirm. Once that happens, you have a login to
gnuradio.org but are not yet a member of a project; what’s called,
appropriately, a “non-member.” To do many things on the website, you
to be a member of that particular project, which means manual
by one of the website admins. All that means is that you ping me to make
you a member of GNU Radio, at which point you can now post and edit.

We wanted to have bug fixes and ticket tracking open to everyone, but
someone had to go and ruin it for everyone. The process isn’t a big
though, and you can always use guest:gnuradio.