On svn-auth-x509 branch, following to r1618902, fix a typo.

* subversion/libsvn_subr/x509info.c
  (svn_x509_certinfo_get_subject_cn): Fix the name to use '_' instead of '-'.


git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/svn-auth-x509@1618903 13f79535-47bb-0310-9956-ffa450edef68