Issue Tracker hook creates duplicate issue log entries (BB-3003)

The issue tracker service creates multiple log entries in an issue report when a branch is merged into another branch and then that branch is pushed.

Example:
Create issue which gives an id of BCLOUD-5.

#!bash

git commit -a -m 'My log. Fixes BCLOUD-5'
git push origin master
git checkout production
git merge master
git push origin production