bugfix: don't resubscribe if isPathQuery

The case:

Server rendering, unbundleing. Racer don't resubscribe to serialized docs for queries with ids-path (f.e. model.query('users', '_page.userIds')).

Racer subscribes only to new-docs (which will be added after reactive-function changes '_page.userIds'). But all serialized/deserialized '_page.userIds' docs stay without subscription.

You can try to recreate the bug using chat from derby-examples. After some chating (using two browsers or usual/incognito tabs) press f5, and then change user-name at the another tab. The name don't be changed in the first tab.