Bug 28424: (28370 follow-up) Fix response definition

Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>

Signed-off-by: David Nind <david@davidnind.com>

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>

api/v1/swagger/paths/patrons_account.json

@@ -88,7 +88,7 @@
         "201": {
           "description": "Credit added",
           "schema": {
-            "type": "object"
+            "$ref": "../definitions.json#/account_line"
           }
         },
         "401": {