Chromium Windows Perf bot fix. Tolerate CR at the end of the line that contains the timestamp.

* Scripts/webkitpy/common/checkout/scm/svn.py:
(SVN.timestamp_of_latest_commit):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@143839 268f45cc-cd09-0410-ab3c-d52691b4dbfc