fix contrib/hooks/post-receive-email hooks.recipients error message

Have the error message for missing recipients actually report the
missing config variable and not a fictional one.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

contrib/hooks/post-receive-email

@@ -138,7 +138,15 @@ generate_email()
 
 	# Check if we've got anyone to send to
 	if [ -z "$recipients" ]; then
-		echo >&2 "*** hooks.recipients is not set so no email will be sent"
+		case "$refname_type" in
+			"annotated tag")
+				config_name="hooks.announcelist"
+				;;
+			*)
+				config_name="hooks.mailinglist"
+				;;
+		esac
+		echo >&2 "*** $config_name is not set so no email will be sent"
 		echo >&2 "*** for $refname update $oldrev->$newrev"
 		exit 0
 	fi