Suggest vlc-dbg for mod_vlc

This helps to reason about any core dumps that come from libvlc /
mod_vlc.

debian/control-modules

@@ -537,6 +537,7 @@ Description: VLC streaming
  This module provides VLC streaming.
 Build-Depends: libvlc-dev (>= 2.0.0)
 Depends: vlc-nox
+Suggests: vlc-dbg
 Distro-Conflicts: squeeze
 
 ## mod/languages