Fix the WriteOptions gso default value - it should be disabled

Summary: Fix the WriteOptions gso default value - it should be disabled

Reviewed By: danobi

Differential Revision: D25313187

fbshipit-source-id: 581f41d9da48405092eef303630aaa88b18d1da0

folly/io/async/AsyncUDPSocket.h

@@ -141,7 +141,7 @@ class AsyncUDPSocket : public EventHandler {
     WriteOptions() = default;
     WriteOptions(int gsoVal, bool zerocopyVal)
         : gso(gsoVal), zerocopy(zerocopyVal) {}
-    int gso{1};
+    int gso{0};
     bool zerocopy{false};
   };