BUG/MINOR: vars: do not talk about global section in CLI errors for set-var

When attempting to set a variable does not start with the "proc" scope on
the CLI, we used to emit "only proc is permitted in the global section"
which obviously is a leftover from the initial code.

This may be backported to 2.4.
diff --git a/src/vars.c b/src/vars.c
index e4e547a..59f802a 100644
--- a/src/vars.c
+++ b/src/vars.c
@@ -1039,7 +1039,7 @@
 		goto fail;
 
 	if (rule.arg.vars.scope != SCOPE_PROC) {
-		memprintf(&err, "'%s %s': cannot set variable '%s', only scope 'proc' is permitted in the global section.", args[0], args[1], args[2]);
+		memprintf(&err, "'%s %s': cannot set variable '%s', only scope 'proc' is permitted here.", args[0], args[1], args[2]);
 		goto fail;
 	}