CLEANUP: mux-h1: use "H1" and not "h1" as the mux's name

The mux's name is the only one reported in lower case in "show sess"
or "haproxy -vv" while the other ones are upper case, so it loses and
the other ones win :-)

src/mux_h1.c

@@ -2390,7 +2390,7 @@ static const struct mux_ops mux_h1_ops = {
 	.show_fd     = h1_show_fd,
 	.reset       = h1_reset,
 	.flags       = MX_FL_HTX,
-	.name        = "h1",
+	.name        = "H1",
 };