Request form not being updated when removing required option from custom field

Summary

when changing the  required option for a custom field used for a request form,  AO_54307E_VIEWPORTFIELD isn't being updated (the cache doesn't appear to be cleared either, therefor you get this error:

This is similar to JSDSERVER-5782 but different as you're not deleting the custom field just changing the required option:

Steps to reproduce 

1.  Create a new custom field.
2. Set the custom field to be Required.
3. Add the custom field to a service desk screen 
4. Add the Custom field in the Request type field. (Project Settings > Request types > Edit fields > Add field > Select (Custom field).
5. Set the custom field to Optional
6. remove the custom field from the service desk screen
7. try to edit the request type fields

Expected Behavior

Service Desk will now allow you to remove the field

Actual Behavior

Service Desk throws an error "Cannot delete a field that is required by Jira or Jira Service Desk."

Cause

When the custom field is set to optional the REQUIRED field in AO_54307E_VIEWPORTFIELD table isn't being updated for the request type:

Workaround: 

1. Run below SQL to list out the Request types in the Service Desk

    SELECT * from "AO_54307E_VIEWPORTFORM";

   Take note of the ID of the affected request types

2. Run below SQL to list all the field in the request type affected.

    SELECT * FROM "AO_54307E_VIEWPORTFIELD" where "FORM_ID" = <ID from Previous query>;

3. Update the deleted custom field value and set the required value to 'f'

   UPDATE "AO_54307E_VIEWPORTFIELD" SET "REQUIRED" = 'f' where "ID" =<ID for relevant custom field>';

4. Either restart JIRA OR to clear the Request form cache simply navigate to another Service Desk project and edit and save a Request Type that is NOT using the same screen as the affected project, this should flush the Request form cache.