contrib: update OpenDHT to 1.7.2

Change-Id: I1a8f5973cbb5027f4a1ccc3d51029a034bd5c988
Reviewed-by: Sebastien Blin <sebastien.blin@savoirfairelinux.com>

contrib/src/opendht/SHA512SUMS

-e7ce62d26f0c9b4c0beefd6b950ced9f6fa92fda905ebf19f287d13b1c9b4c9d3834e2f89a508dbb440c22f25a9f4259e57c6f0f5647694e07cf50bca69f4d96  opendht-1.7.2rc2.tar.gz
+dcb70c8f38f067f1035cbfdc7897a8245bacaef547afa48652e56e39e4641f7bb1ea6bc2bf3e46f8454cdbe3743eab318eca9fb6a02921d5f5fa792748a14cd1  opendht-1.7.2.tar.gz

contrib/src/opendht/rules.mak

 # OPENDHT
-OPENDHT_VERSION := 1.7.2rc2
+OPENDHT_VERSION := 1.7.2
 OPENDHT_URL := https://github.com/savoirfairelinux/opendht/archive/$(OPENDHT_VERSION).tar.gz
 
 PKGS += opendht