Add null check to hand patch

bungee/src/main/java/us/myles/ViaVersion/bungee/listeners/MainHandPatch.java

@@ -33,6 +33,7 @@ public class MainHandPatch implements Listener {
             return;
 
         UserConnection user = Via.getManager().getConnection(event.getPlayer().getUniqueId());
+        if(user == null) return;
         
         try {
             if (user.get(ProtocolInfo.class).getPipeline().contains(Protocol1_9TO1_8.class)) {