Fixed a missing parenthesis typo.

(PS: I created a GitLab account just to submit this typo fix. The signup process required a lot of needless stuff that wasted a bunch of my time and which has no current relevance whatsoever to what I'm doing e.g. creating a group and project when I have no interest in doing so etc. Perhaps you should switch to a site that has much better understanding of basic user interface/experience design. The experience has definitely left a negative initial impression of GitLab's sense of judgement and taste compared to e.g. GitHub etc.)