patch 9.0.1269: channel test often fails on Mac OS

Problem:    Channel test often fails on Mac OS.
Solution:   Increase the wait time from one to 15 milliseconds. (D. Ben
            Knoble, closes #11894)

Author: brammool

src/channel.c

@@ -979,11 +979,13 @@ channel_open(
 
 	ch_log(channel, "Trying to connect to %s port %d", dst, port);
 
-	// On Mac and Solaris a zero timeout almost never works.  At least wait
-	// one millisecond.  Let's do it for all systems, because we don't know
-	// why this is needed.
+	// On Mac and Solaris a zero timeout almost never works.  Waiting for
+	// one millisecond already helps a lot.  Later Mac systems (using IPv6)
+	// need more time, 15 milliseconds appears to work well.
+	// Let's do it for all systems, because we don't know why this is
+	// needed.
 	if (waittime == 0)
-	    waittime = 1;
+	    waittime = 15;
 
 	sd = channel_connect(channel, addr->ai_addr, (int)addr->ai_addrlen,
 								   &waittime);

src/version.c

@@ -695,6 +695,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1269,
 /**/
     1268,
 /**/