package/musl-fts: add an upstream URL to Config.in

Add an upstream URL to the help text in Config.in. This
addresses the 'Missing' URL status in the package stats
web page output.

Signed-off-by: Mark Corbin <mark@dibsco.co.uk>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/musl-fts/Config.in

@@ -5,3 +5,5 @@ config BR2_PACKAGE_MUSL_FTS
 	  The musl-fts package implements the fts(3) functions
 	  fts_open, fts_read, fts_children, fts_set and fts_close,
 	  which are missing in musl and uClibc-ng C libraries.
+
+	  https://github.com/void-linux/musl-fts