ra_serf: Use case-insensitive hostname comparision when validating server 
certificate as it specified in RFC 2459.

* subversion/libsvn_ra_serf/util.c
  (ssl_server_cert): Use APR_FNM_CASE_BLIND flag when matching 
   server certificate hostname.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1514763 13f79535-47bb-0310-9956-ffa450edef68