contrib: don't build opendht documentation

The CMake option to build OpenDHT's documentation was already disabled
on Linux but not on Windows.

Change-Id: I66b29e68cc64596ca3066122c27facd871620d05

contrib/src/opendht/package.json

@@ -14,6 +14,7 @@
     "defines": [
         "BUILD_SHARED_LIBS=0",
         "BUILD_TESTING=0",
+        "OPENDHT_DOCUMENTATION=0",
         "OPENDHT_SHARED=0",
         "OPENDHT_PROXY_CLIENT=1",
         "OPENDHT_PROXY_SERVER=1",