alsamixergui: fix long help text lines

Select fltk and fix homepage link while we're at it.

package/alsamixergui/Config.in

@@ -1,6 +1,7 @@
 config BR2_PACKAGE_ALSAMIXERGUI
+	select BR2_PACKAGE_FLTK
 	bool "alsamixergui"
 	help
 	  A nice GUI mixer for Alsa using fltk
 
-	  http://snapshot.debian.net/archive/2008/03/19/debian/pool/main/a/alsamixergui
+	  http://www.iua.upf.es/~mdeboer/projects/alsamixergui/