Add dealing with newlines for editor to 5.1-to-6.0

backport of https://github.com/gitlabhq/gitlabhq/commit/2d681c0d1ed14bf23c041aa04fa3e77caceda9a1
Merge pull request #7438 from bbodenmiller/patch-5

Add dealing with newlines for editor to 5.1-to-6.0