This is to make sure we doint call change.topic which will throw an null
per below.
I was getting an undefined error
gr-app.js:2746 Uncaught (in promise) TypeError: Cannot read property 'topic' of null
at gr-app.js:2746
at <anonymous>
when debugging https://gerrit-review.googlesource.com/#/c/108092/
Change-Id: Ie9802cdf8a601570a6f8352054c8cd042e348792