iDrac virtual media install fails on Some hardware (Observed on a Dell 640 with firmware version 4.20.20.20 and possibly 3.34.34.34 )

This results in master nodes failing to provision when using vmedia, with

2020-08-27 13:27:05.862 1 DEBUG ironic.drivers.modules.drac.boot [req-e98c89cd-bfb3-4ee9-9e24-4473d72263a1 - - - - -] Sushy OEM extension Python package 'sushy-oem-idrac' failed to set virtual boot device with system 4c4c4544-0048-3710-8050-b3c04f505832 manager 3258504f-c0b3-5080-3710-00484c4c4544 for node 458cd6f7-f6a0-45ce-88a0-2b3bf2038a3c. Will try next manager, if available. Error: Sushy Extension Error: Response 202 to HTTP POST with args ('/redfish/v1/Managers/iDRAC.Embedded.1/Actions/Oem/EID_674_Manager.ImportSystemConfiguration',), kwargs {'data': {'ShareParameters': {'Target': 'ALL'}, 'ImportBuffer': '<SystemConfiguration><Component FQDD="iDRAC.Embedded.1"><Attribute Name="ServerBoot.1#BootOnce">Enabled</Attribute><Attribute Name="ServerBoot.1#FirstBootDevice">VCD-DVD</Attribute></Component></SystemConfiguration>'}} does not include Location: in header _set_boot_device /usr/lib/python3.6/site-packages/ironic/drivers/modules/drac/boot.py:144^[[00m


Details copied from https://storyboard.openstack.org/#!/story/2007640

When a GET request is performed on an asynchronous operation task monitor URI, the iDRAC service can return the HTTP 202 Accepted status code without a Location header. This has been observed with at least iDRAC firmware versions 3.30.30.30 and 4.10.10.10 for 14th generation hardware (14G) when issuing a request for the long-running OEM Server Configuration Profile (SCP) import and export system configuration operations. [1] sushy-oem-idrac requires the Location header to continue to query the status of the operation, and determine when it has completed and whether it succeeded.