Explicit returned value is missing

[chinesedfan]

• I have searched the issues of this repository and believe that this is not a duplicate.

Expected Behavior

When I was reading source codes of next.js, I found an interesting place, https://github.com/zeit/next.js/blob/canary/lib/router/router.js#L138.

We'd better to return true there? Those codes were introduced by #1250.

Current Behavior

Return without explicit boolean value.

[arunoda]

@chinesedfan Thanks for the issue.
We just fixed it.