WORKSPACE: Fix the httpcore-nio reference typo

Change-Id: I884dc7bd2900c73168eb48637f9964b27613c61e

WORKSPACE

diff --git a/WORKSPACE b/WORKSPACE
index dc4c906..c8417d2 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -888,7 +888,7 @@
     sha1 = "76716d529710fc03d1d429b43e3cedd4419f78d4",
 )
 
-# When upgrading elasticsearch-rest-client, also upgrade http-niocore
+# When upgrading elasticsearch-rest-client, also upgrade httpcore-nio
 # and httpasyncclient as necessary.
 maven_jar(
     name = "elasticsearch-rest-client",