[ETCM-355] Move fallback on NetworkMessageDecoder inside .ehtMessageDecoder

Author: lukasz-golebiewski

src/main/scala/io/iohk/ethereum/network/p2p/MessageDecoders.scala

@@ -110,9 +110,9 @@ object EthereumMessageDecoder {
   type Decoder = (Int, Array[Byte]) => Message
   def ethMessageDecoder(protocolVersion: Capability): MessageDecoder =
     protocolVersion match {
-      case Capability.Capabilities.Etc64Capability => ETC64MessageDecoder.fromBytes
-      case Capability.Capabilities.Eth63Capability => ETH63MessageDecoder.fromBytes
-      case Capability.Capabilities.Eth64Capability => ETH64MessageDecoder.fromBytes
+      case Capability.Capabilities.Etc64Capability => ETC64MessageDecoder.orElse(NetworkMessageDecoder)
+      case Capability.Capabilities.Eth63Capability => ETH63MessageDecoder.orElse(NetworkMessageDecoder)
+      case Capability.Capabilities.Eth64Capability => ETH64MessageDecoder.orElse(NetworkMessageDecoder)
       case _                                       => throw new RuntimeException(s"Unsupported Protocol Version $protocolVersion")
     }
 }

src/main/scala/io/iohk/ethereum/network/rlpx/RLPxConnectionHandler.scala

@@ -396,7 +396,7 @@ object RLPxConnectionHandler {
       negotiated: Capability,
       p2pVersion: Long
   ): MessageCodec = {
-    val md = EthereumMessageDecoder.ethMessageDecoder(negotiated).orElse(NetworkMessageDecoder)
+    val md = EthereumMessageDecoder.ethMessageDecoder(negotiated)
     new MessageCodec(frameCodec, md, p2pVersion)
   }