Ticket 48363 - Support for rfc3673 '+' to return operational attributes

Description: commit 08c40e8a35a3611a0ac3ca30a86d40a17676ba84 had a copy&
paste error.  Replacing slapi_rwlock_unlock with slapi_rwlock_rdlock.

ldap/servers/slapd/features.c

@@ -44,7 +44,7 @@ slapi_register_supported_feature( char *featureoid )
 int
 slapi_get_supported_features_copy( char ***ftroidsp )
 {
-    slapi_rwlock_unlock(supported_features_lock);
+    slapi_rwlock_rdlock(supported_features_lock);
     if ( ftroidsp != NULL ) {
         *ftroidsp = charray_dup(supported_features);
     }