Vendor-Specific attribute with rlm_rest

[Michael A Carpenter - macarpen@us.ibm.com]

>  OK.  I'll have to take a deeper look into it.  I think it can be fixed without too much effort.  I just don't want to break anything else.
> 
>  I spent some time trying to find workarounds, and it looks hard.  :(  The "users" file allows "Attr-26 := 0x...".  But the "unlang" parser doesn't allow that.  The reasons are esoteric and a bit hard to fix.

Thanks for taking a look. Would you prefer I created a GitHub issue to track it?