Update intent of socketToFd in changelog

Author: eborden

CHANGELOG.md

@@ -1,7 +1,7 @@
 ## Version 3.1.1.0
 
-* socketToFd: Allows converting a socket to a file desriptor without risking
-  closing the socket.
+* socketToFd: Duplicates a socket as a file desriptor and closes the source
+  socket.
   [#424](https://github.com/haskell/network/pull/424)
 * A new API: gracefulClose.
   [#417](https://github.com/haskell/network/pull/417)