docs: fixed not supported code-block

docs/api/methods/deprecated-methods.rst

@@ -38,7 +38,7 b' changeset_comment'
 
    Example error output:
 
-   .. code-block:: json
+   .. code-block:: javascript
 
        {
            "id" : <id_given_in_input>,

rhodecode/api/views/deprecated_api.py

@@ -66,7 +66,7 b' def changeset_comment(request, apiuser, '
 
     Example error output:
 
-    .. code-block:: json
+    .. code-block:: javascript
 
         {
             "id" : <id_given_in_input>,