Some tap targets too close to each other on mobile

Summary

Self-explanitory, see https://developers.google.com/speed/pagespeed/insights/?url=https%3A%2F%2Fgitlab.com%2Fgitlab-org%2Fgitlab-ce%2Fissues%2F

Fix

Increase the padding. So far as I can see, this should be doable without requiring any changes to the actual layout - there's enough space around the elements that are marked as problematic to add some more breathing room.