Fix Transformer rendering issue

- Switching modes between transform up/down now correctly schedules a
  rendering update

Author: Exaxxion

src/main/java/gregtech/common/metatileentities/electric/MetaTileEntityTransformer.java

@@ -73,6 +73,7 @@ public void receiveCustomData(int dataId, PacketBuffer buf) {
         super.receiveCustomData(dataId, buf);
         if (dataId == 100) {
             this.isTransformUp = buf.readBoolean();
+            getHolder().scheduleChunkForRenderUpdate();
         }
     }