debian: don't build mod_managed

It's broken too many of my recent builds.  We can add it back in when
things stabilize or perhaps after we get it to swig with a recent
version of swig that we can make part of the clean bootstrap/build
process.

debian/bootstrap.sh

@@ -31,6 +31,7 @@ avoid_mods=(
   endpoints/mod_reference
   endpoints/mod_unicall
   formats/mod_shout
+  languages/mod_managed
   languages/mod_spidermonkey
   sdk/autotools
   xml_int/mod_xml_ldap