package/rp-pppoe: update website url

The website for rp-pppoe moved from Roaring Penguin's main site to
a personal project page.

Signed-off-by: Matthew Weber <matthew.weber@rockwellcollins.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
(cherry picked from commit 02af305b5c94a484ef0a393a722ec88792d9aa6f)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/rp-pppoe/Config.in

@@ -16,4 +16,4 @@ config BR2_PACKAGE_RP_PPPOE
 	  devices. Otherwise the normal client functionality already
 	  exists in the pppd package (and kernel).
 
-	  http://www.roaringpenguin.com/pppoe.html
+	  https://dianne.skoll.ca/projects/rp-pppoe/