Process Instance Diagram has wrong content-type

Description

The Process Instance Diagram has the content-type "application/json" which is clearly wrong as it is a binary png.
This may cause problems with deserialization on the client side.

I've attached a patch to set the content-type to the correct one.

Environment

None

Assignee

Tijs Rademakers

Reporter

Leonard Br_nings

Labels

None

Components

Fix versions

Affects versions

Priority

Major
Configure