Allow to open pull popup from within log view

[gollth]

Another small thing, that worked in Magit: When pressing p in the log graph view you could open the "pull" popup. On my setup this fails with:

Added this open to the pop up mappings in log_view:

[CKolkey]

Ah, ok! The implementation is actually even more simple than you have it - we don't do anything with the passed in commit, so you can omit that second function as an argument entirely. Since it's so simple I just went ahead and did it: #972

Thanks for pointing that out :)

[gollth]

Ah okay, good to know. Thanks for fixing!