The example hook script 'detect-merge-conflicts.sh' was too eager to reject
a commit, since a single added line of "=======" was interpreted as a
conflict marker, and that line occurs reasonably often in normal text files.
Only look for the beginning and end marker lines, because they are more
distinctive.

* contrib/hook-scripts/detect-merge-conflicts.sh
  Don't look for "=======".


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1466758 13f79535-47bb-0310-9956-ffa450edef68