Handle nested location lookup error

Previously, when looking up a nested location after a prefix location
match, the nested regex or predicate match error could be ignored if
more regex or predicate locations were configured at the current level.
Now such error leads to request finalization.

src/http/ngx_http_core_module.c

@@ -1470,7 +1470,7 @@ ngx_http_core_find_location(ngx_http_request_t *r)
         rc = ngx_http_core_find_location(r);
     }
 
-    if (rc == NGX_OK || rc == NGX_DONE) {
+    if (rc == NGX_OK || rc == NGX_DONE || rc == NGX_ERROR) {
         return rc;
     }