Config.in.legacy: remove redundant empty line

As reported by check-package.

Fixes: https://gitlab.com/buildroot.org/buildroot/-/jobs/1003192260

Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

Config.in.legacy

@@ -152,7 +152,6 @@ config BR2_BINUTILS_VERSION_2_33_X
 	help
 	  binutils 2.33.x has been removed, use a newer version.
 
-
 config BR2_PACKAGE_LIBUPNP18
 	bool "libupnp18 package removed"
 	select BR2_LEGACY