opendht: bump version

Bump OpenDHT to 2ed99db9.
No significant change since 3.3 except adding the argon2
dependency to the pkgconfig file, fixing the build in some
contrib configurations.

Change-Id: I6809c459e8c241de7654478a542c7a9d4bff4415

contrib/src/opendht/rules.mak

 # OPENDHT
-OPENDHT_VERSION := 1.3.3
+OPENDHT_VERSION := 2ed99db9b1ec167327ef8fd7bfa2603b4f1ea009
 OPENDHT_URL := https://github.com/savoirfairelinux/opendht/archive/$(OPENDHT_VERSION).tar.gz
 
 PKGS += opendht