contrib: update restbed

* Update restbed to latest master 
* Removed dropped Kashmir dependency
* Removed merged/obsolete patches (locale, async read, strand)
* Use branch including necessary findopenssl changes for contrib

Change-Id: I6cdf7de1005f82abeac77eb6bfb0002df83c8017
Reviewed-by: Philippe Gorley <philippe.gorley@savoirfairelinux.com>