Fix regression leading to SSP disconnecting

Fixes #166

Author: Su5eD

fabric-networking-api-v1/src/main/java/net/fabricmc/fabric/mixin/networking/NetworkRegistryMixin.java

@@ -90,7 +90,7 @@ private static Map<ConnectionProtocol, NegotiationResult> preserveSendableChanne
             NegotiationResult negotiation = results.get(ConnectionProtocol.PLAY);
             List<NegotiatedNetworkComponent> components = new ArrayList<>(negotiation.components());
             channels.stream()
-                .filter(c -> PayloadTypeRegistryImpl.PLAY_S2C.get(c.id()) != null)
+                .filter(c -> components.stream().noneMatch(d -> c.id().equals(d.id())) && PayloadTypeRegistryImpl.PLAY_S2C.get(c.id()) != null)
                 .forEach(c -> components.add(new NegotiatedNetworkComponent(c.id(), c.version())));
             results.put(ConnectionProtocol.PLAY, new NegotiationResult(components, negotiation.success(), negotiation.failureReasons()));
         }

ffapi.gradle.properties

@@ -1,7 +1,7 @@
 loom.platform=neoforge
 fabric.loom.dontRemap=true
 
-implementationVersion=2.0.17
+implementationVersion=2.0.18
 
 versionMc=1.21.1
 versionForge=21.1.57