Fix crlf to lf-only for third_party/README.chromium.template

We should use LF-only unless it is really necessary (e.g. .BAT files).
Probably this was introduced by crrev.com/250068.

BUG=none
TBR=mnaganov@chromium.org, darin@chromium.org

Review URL: https://codereview.chromium.org/162763002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@250962 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 250962