contrib: update opendht

Change-Id: Ifeeb67ee2fb8d7b9fda07a8c3b3183d2683703c6

contrib/src/opendht/SHA512SUMS

-5aaad5a281d599413bd9d60b4268027e12d23d7c58457834518bbf27aefeb95c4f4b1e713e15cbfe4ef34c9b579c421bc22cfbea27387d66374788d465e442a3  opendht-2.0.0rc4.tar.gz
+fb783a186bbe4fc66339c9e37ea987c6bf3c035a3d9f6737e264171709cff74ffa761dee1e13ad7ab0dab090f12d6a326d171127666da1f54e972bd2fa0fe3e1  opendht-2.0.0.tar.gz

contrib/src/opendht/package.json

 {
     "name": "opendht",
-    "version": "2.0.0rc4",
+    "version": "2.0.0",
     "url": "https://github.com/savoirfairelinux/opendht/archive/__VERSION__.tar.gz",
     "deps": [
         "argon2",

contrib/src/opendht/rules.mak

 # OPENDHT
-OPENDHT_VERSION := 2.0.0rc4
+OPENDHT_VERSION := 2.0.0
 OPENDHT_URL := https://github.com/savoirfairelinux/opendht/archive/$(OPENDHT_VERSION).tar.gz
 
 PKGS += opendht