[gloo] reenable libuv build (2/N)

Summary:
As part of reviving CI, reenable libuv that is causing CI errors.

Test Plan:
Test on github.

Reviewers:

Subscribers:

Tasks:

Tags:

ghstack-source-id: 11b29816c437751996085033269cef5e005775b3
Pull Request resolved: #396

gloo/CMakeLists.txt

@@ -94,13 +94,12 @@ else()
   set(GLOO_HAVE_TRANSPORT_IBVERBS 0)
 endif()
 
-# TODO: turn ths back on once tests are passing again.
 # Compile uv transport if libuv is available
-#if(USE_LIBUV)
-# set(GLOO_HAVE_TRANSPORT_UV 1)
-#else()
-#  set(GLOO_HAVE_TRANSPORT_UV 0)
-#endif()
+if(USE_LIBUV)
+  set(GLOO_HAVE_TRANSPORT_UV 1)
+else()
+  set(GLOO_HAVE_TRANSPORT_UV 0)
+endif()
 
 add_subdirectory(common)
 add_subdirectory(mpi)