Fix a thinko.

* subversion/include/private/svn_subr_private.h
* subversion/libsvn_subr/config.c
  (svn_config__get_default_config): Change return type.

* subversion/svn/svn.c
* subversion/svnmucc/svnmucc.c
  (sub_main): Handle return type.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1591016 13f79535-47bb-0310-9956-ffa450edef68