patch 8.2.2118: dead code in the job support

Problem:    Dead code in the job support. (Dominique Pellé)
Solution:   Define USE_ARGV before checking for it.

src/job.c

@@ -887,6 +887,11 @@ job_any_running()
 }
 #endif
 
+// Unix uses argv[] for the command, other systems use a string.
+#if defined(UNIX)
+# define USE_ARGV
+#endif
+
 #if !defined(USE_ARGV) || defined(PROTO)
 /*
  * Escape one argument for an external command.
@@ -1269,9 +1274,7 @@ job_start(
     char	**argv = NULL;
     int		argc = 0;
     int		i;
-#if defined(UNIX)
-# define USE_ARGV
-#else
+#ifndef USE_ARGV
     garray_T	ga;
 #endif
     jobopt_T	opt;

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2118,
 /**/
     2117,
 /**/