conf: fix segfault if a shared module is loaded and dynamic configuration used

When executing conf-commit, the server_reload() function triggers conf_free(),
causing all shared modules to unload. These modules are subsequently referenced
by module hooks from the nameserver, or the configuration schema is accessed
during the process of merging schemas.

This fix preserves the shared modules by relocating the current module context
to the cloned configuration, thus preventing the old configuration from purging
the modules.