Fix another test that was missed, where generics interact badly with …

…varargs

enterprise/causal-clustering/src/test/java/org/neo4j/causalclustering/catchup/tx/TxStreamFinishedResponseEncodeDecodeTest.java

@@ -38,7 +38,8 @@ public void shouldEncodeAndDecodePullRequestMessage()
 
         // when
         channel.writeOutbound( sent );
-        channel.writeInbound( channel.readOutbound() );
+        Object message = channel.readOutbound();
+        channel.writeInbound( message );
 
         // then
         TxStreamFinishedResponse received = channel.readInbound();