[Bug Report] Discarded `:` in Help Buffer's Ex Mode
@fox0430

This is a minor visual bug.

With the latest available repository state of Moe, open any file.  Now, call `:help` and switch to the help buffer.  If the help buffer is active, the initial `:` in Ex Mode will be discarded visually, and only visually; any command will work as usual.  This only affects the help buffer if it is opened and active.