Ignore emacs autosave files in source-repositories

source-repositories uses find to discover things it should import. If
someone happens to use emacs, and happens to have had an autosave file
in a directory with a wildly broken version of a source-repositories-
file, then dib will attempt to execute the contents of the autosave file
and the user will be sad. Adding a filter to the find command for files
ending in ~ will prevent pain and suffering.

Change-Id: I27c8a4b53d3c9b913ca926db16b4271941f6fb5d
Merge "Ignore emacs autosave files in source-repositories"