MMNoTitleBarWindowKey for hiding titlebar doest not work properly

[mirca]

As reported by a few users, looks like the solution merged in #111 is not working as intended.

I'm using macOS Sierra 10.12.5 and MacVim 8.0.891 (136).

PS: Sorry if this is a duplicate

[garbagemule]

Possible duplicate: #490

[ychin]

Dup of #490