Drop executable bit from AUTHORS

TBR=gnanasekar.s@samsung.com
NOTRY=true

Review URL: https://codereview.chromium.org/100053010

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@239455 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 239455