patch 7.4.1536

Problem:    Cannot re-use a channel for another job.
Solution:   Add the "channel" option to job_start().

src/version.c

@@ -743,6 +743,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1536,
 /**/
     1535,
 /**/