Fix Netty upgrade to wait for all jobs completion

Too early channel close caused Windows to mark connection as aborted so test client is unable to read close frame

ktor-server/ktor-server-netty/jvm/src/io/ktor/server/netty/http1/NettyHttp1ApplicationResponse.kt

@@ -99,6 +99,7 @@ internal class NettyHttp1ApplicationResponse(call: NettyApplicationCall,
         }
 
         (call as NettyApplicationCall).responseWriteJob.join()
+        job.join()
 
         context.channel().close()
     }