mod_admin_shell: Make Role and Affiliation columns the same width for aesthetics
The length of the title "Affiliation" made them both close enough that
it looked off.
For full information on our dependencies, version requirements, and
where to find them, see https://prosody.im/doc/depends
If you have luarocks available on your platform, install the following:
- luaexpat
- luasocket
- luafilesystem
- luasec