SslHandler#handlerRemoved0() shouldn't care about the SSLEngine being…

… a specific type but only if it's ReferenceCounted

Motivation

SslHandler should release any type of SSLEngine if it implements the ReferenceCounted interface

Modifications

Change condition to check for ReferenceCounted interface

Result

Better use of interfaces

handler/src/main/java/io/netty/handler/ssl/SslHandler.java

@@ -34,6 +34,7 @@
 import io.netty.channel.PendingWriteQueue;
 import io.netty.handler.codec.ByteToMessageDecoder;
 import io.netty.handler.codec.UnsupportedMessageTypeException;
+import io.netty.util.ReferenceCounted;
 import io.netty.util.concurrent.DefaultPromise;
 import io.netty.util.concurrent.EventExecutor;
 import io.netty.util.concurrent.Future;
@@ -580,8 +581,8 @@ public void handlerRemoved0(ChannelHandlerContext ctx) throws Exception {
             // Check if queue is not empty first because create a new ChannelException is expensive
             pendingUnencryptedWrites.removeAndFailAll(new ChannelException("Pending write on removal of SslHandler"));
         }
-        if (engine instanceof ReferenceCountedOpenSslEngine) {
-            ((ReferenceCountedOpenSslEngine) engine).release();
+        if (engine instanceof ReferenceCounted) {
+            ((ReferenceCounted) engine).release();
         }
     }