Remove extra chars in launchpad bug links

Add a new commentlink section in gerrit.config that parses
launchpad bug links pattern and removes any trailing char
after the bug number, to prevent including dots, question marks
or any other trailing char to be included in the link

Closes-Bug: 1222217

Change-Id: I402b75cea39cda01829bee6b1762e9abe54d85d4
Merge "Remove extra chars in launchpad bug links"