Force netty downgrade on dedicated server to match client. Netty bug: https://github.com/netty/netty/issues/2302 Closes #1848

fml/jsons/1.8-rel.json

@@ -26,6 +26,11 @@
       "name": "@artifact@",
       "url": "http://files.minecraftforge.net/maven/"
     },
+    {
+	  "comment": "Force the downgrade on dedicated server to match client. Netty bug: https://github.com/MinecraftForge/MinecraftForge/issues/1848",
+      "name": "io.netty:netty-all:4.0.15.Final",
+      "serverreq":true
+    },
     {
       "name": "net.minecraft:launchwrapper:1.11",
       "serverreq":true