Reenable mod_v8 in debian package builds

The relevant v8 build issues are believed to be worked out at this
point.

debian/bootstrap.sh

@@ -29,7 +29,6 @@ avoid_mods=(
   endpoints/mod_unicall
   languages/mod_managed
   languages/mod_perl
-  languages/mod_v8
   sdk/autotools
   xml_int/mod_xml_ldap
   xml_int/mod_xml_radius