package/matchbox-startup-monitor: 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>
(cherry picked from commit 56fff9ef97fe231e2f118a1365ff000f9d77365e)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/matchbox-startup-monitor/Config.in

@@ -4,3 +4,5 @@ config BR2_PACKAGE_MATCHBOX_STARTUP_MONITOR
 	select BR2_PACKAGE_STARTUP_NOTIFICATION
 	help
 	  Matchbox Panel Startup Monitor Applet.
+
+	  http://git.yoctoproject.org/cgit.cgi/mb-applet-startup-monitor/