Dejagnu unreachable

[yvantor]

During submodule update:

error: Server does not allow request for unadvertised object 98d75813f06ff2b0bb0d721558fce51db7e9ca6e
fatal: Fetched in submodule path 'dejagnu', but it did not contain 98d75813f06ff2b0bb0d721558fce51db7e9ca6e. Direct fetching of that commit failed.

Clicking on the dejagnu submodule prompts to 404 web page

[cmuellner]

This happens whenever they push new changes to DejaGnu upstream.
Fix can be found here: #1784