Pull mod_verto from debian packaging temporarily

`make install` on mod_verto needs to be reworked a bit for packaging
builds.

debian/bootstrap.sh

@@ -27,6 +27,7 @@ avoid_mods=(
   endpoints/mod_opal
   endpoints/mod_reference
   endpoints/mod_unicall
+  endpoints/mod_verto
   languages/mod_managed
   sdk/autotools
   xml_int/mod_xml_ldap