www/waterfox: flatten line endings after r461193

Subversion doesn't allow mixed line endings when svn:eol-style
property is set. files/patch-bug1402766 tries to create a new test
file, so simply strip carriage-return from lines which is what
actually happens on checkout. Originally, the file landed via
git-svn which doesn't appear to run sanity checks on dcommit.

$ svn cat files/patch-bug1402766
svn: E135000: Inconsistent line ending style

Reported by: gjb