Plugin crashes Sketch upon opening any file after the new Sketch 41.2 update 
Hello!

I just upgraded Sketch to v41.2.  Now Sketch crashes every time I open any file (even a new file).  Sketch claimed that they believe it was due to some plugins, so I diagnosed the issue by disabling all my Sketch plugins and then one-by-one reenabling them until the crashing started again.

When I reenabled this Git-Sketch-Plugin the crashing resumed.  I also reconfirmed this issue by enabling **only** this plugin (no other plugins enabled), with the same result.

I tried updating this plugin to the latest version that you just release, but that crashes Sketch as well.  The version of this plugin that I have installed is v0.7.4, and when I double-click on the Git.sketchplugin file for your newest version it immediately crashes Sketch (if it is open) and does not upgrade the plugin.  If I try double-clicking on the file when Sketch is not open, it just fails silently.

Thanks for reading and let me know if you have questions.
