patch 8.2.0786: channel test is flaky on FreeBSD

Problem:    Channel test is flaky on FreeBSD.
Solution:   Set the sockiet TCP_NODELAY option. Adjust expected line count in
            netbeans test. (Ozaki Kiichi, closes #6097)

src/testdir/test_channel.py

@@ -21,6 +21,9 @@ except ImportError:
 
 class ThreadedTCPRequestHandler(socketserver.BaseRequestHandler):
 
+    def setup(self):
+        self.request.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
+
     def handle(self):
         print("=== socket opened ===")
         while True: