[master] f8ea52835 fix -a usage info

[Nils Goroll]

commit f8ea528353a09d6f9c1753c32a0ed446d8033118
Author: Nils Goroll <nils.goroll at uplex.de>
Date:   Tue Apr 30 15:22:12 2019 +0200

    fix -a usage info

diff --git a/bin/varnishd/mgt/mgt_main.c b/bin/varnishd/mgt/mgt_main.c
index 8b1cadcb6..7f6622a01 100644
--- a/bin/varnishd/mgt/mgt_main.c
+++ b/bin/varnishd/mgt/mgt_main.c
@@ -91,7 +91,7 @@ usage(void)
 
 	printf("\nBasic options:\n");
 
-	printf(FMT, "-a address[:port][,proto]",
+	printf(FMT, "-a [<name>=]address[:port][,proto]",
 	    "HTTP listen address and port");
 	printf(FMT, "   [,user=<u>][,group=<g>]",
 	    "Can be specified multiple times.");