contrib: bump OpenDHT to 1.7.0rc5

Change-Id: I95fd87dab26535cf9a2f7df334f5e9d47745491b
Reviewed-by: Sebastien Blin <sebastien.blin@savoirfairelinux.com>

contrib/src/opendht/SHA512SUMS

-38cd7923e4530ce86d62cba452ff9d09c4406a2b1e4559bc309b62ba12c1810bdf8029a08fd6b347634b03cccd9ae4bf776dca72c5562b0a447ce57da20907ee  opendht-1.7.0rc4.tar.gz
+259b3bd0d9b2fabaf93a875e8f4082d0cc9ce9e35b6726b554e6485688dc825d014fad2bf4464bc55f80941f2f0ae365fbea7f6ee0ecda5e08c9d680bf335bc3  opendht-1.7.0rc5.tar.gz

contrib/src/opendht/rules.mak

 # OPENDHT
-OPENDHT_VERSION := 1.7.0rc4
+OPENDHT_VERSION := 1.7.0rc5
 OPENDHT_URL := https://github.com/savoirfairelinux/opendht/archive/$(OPENDHT_VERSION).tar.gz
 
 PKGS += opendht