packages: Make set-base-dbg depend on set-optional-dbg

As set-base depends on set-optional, so should set-base-dbg depend on
set-optional-dbg.  Otherwise, people who install set-base-dbg will be
missing a bunch of debug packages.

MFC after:	1 day
Reviewed by:	emaste
Sponsored by:	https://www.patreon.com/bsdivy
Differential Revision:	https://reviews.freebsd.org/D53575

release/packages/sets/base-dbg.ucl

@@ -28,5 +28,8 @@ deps {
 	},
 	"set-devel-dbg" {
 		version = "${VERSION}"
+	},
+	"set-optional-dbg" {
+		version = "${VERSION}"
 	}
 }