plugin: Do not expect all callbacks to have a plugin context assigned.
plugin: Do not expect all callbacks to have a plugin context assigned.

For callbacks not registered from a plugin, we don't have a context. For
example, the frontend's connection logger callback does not have a context.

tokkee/sysdb,tokkee/sysdb,tokkee/sysdb,sysdb/sysdb,sysdb/sysdb,sysdb/sysdb