Forge: Do not warn when only present on one side

forge/src/main/java/malte0811/ferritecore/ModMainForge.java

@@ -2,8 +2,12 @@ package malte0811.ferritecore;
 
 import cpw.mods.modlauncher.api.INameMappingService;
 import malte0811.ferritecore.util.Constants;
+import net.minecraftforge.fml.ExtensionPoint;
+import net.minecraftforge.fml.ModLoadingContext;
 import net.minecraftforge.fml.common.Mod;
 import net.minecraftforge.fml.common.ObfuscationReflectionHelper;
+import net.minecraftforge.fml.network.FMLNetworkConstants;
+import org.apache.commons.lang3.tuple.Pair;
 
 @Mod(Constants.MODID)
 @Mod.EventBusSubscriber(bus = Mod.EventBusSubscriber.Bus.FORGE)
@@ -13,5 +17,9 @@ public class ModMainForge {
         Constants.blockstateCacheFieldName = ObfuscationReflectionHelper.remapName(
                 INameMappingService.Domain.FIELD, "field_215707_c"
         );
+        ModLoadingContext.get().registerExtensionPoint(
+                ExtensionPoint.DISPLAYTEST,
+                () -> Pair.of(() -> FMLNetworkConstants.IGNORESERVERONLY, (s, b) -> true)
+        );
     }
 }