core.modulemanager: Fix global flag on per-host instances of shared modules (fix #1736)
This flag is something of a shortcut for `module.host == "*"` and should
always be equal to that. Its absence on the proxy object made the
property of the global module instance visible, causing problems such as
with URL reporting in mod_http
== 1.0 ==
- Roster providers
- Clustering
- World domination