Add missing release() call

Signed-off-by: Graham <gpe@openrs2.org>

protocol/src/test/kotlin/org/openrs2/protocol/js5/Js5ResponseEncoderTest.kt

@@ -48,7 +48,9 @@ object Js5ResponseEncoderTest {
         }
 
         read(encoded).use { expected ->
-            assertEquals(expected, channel.readOutbound())
+            channel.readOutbound<ByteBuf>().use { actual ->
+                assertEquals(expected, actual)
+            }
         }
     }