"Temp fix" rescue in note.rb

Commit from January 20, 2012:

# Temp fix to prevent app crash
# if note commit id doesnt exist

And the file as it is today:

# Temp fix to prevent app crash
# if note commit id doesn't exist

Four years of a "temp" fix 😝

rescue is really really slow. So we should probably get rid of that.

cc: @dzaporozhets @rspeicher @yorickpeterse