Foolw-up to r1069791. Fix deprecated calls of svn_config_read.

* subversion/libsvn_subr/config.c
  (read_all,
   svn_config_merge)     : Fixed callers.

* subversion/tests/libsvn_subr/cache-test.c
  (test_memcache_basic,
   test_memcache_longkey): Fixed callers.

* subversion/tests/libsvn_subr/config-test.c
  (test_text_retrieval,
   test_boolean_retrieval,
   test_has_section)     : Fixed callers.

* subversion/svnserve/serve.c
  (load_configs)         : Fixed callers.

* subversion/libsvn_fs_fs/fs_fs.c
  (read_config)          : Fixed callers.

Patch by: Arwin Arni <arwin{_AT_}collab.net>