[bug 896649] Fix clicking on clustered pins opens every single pin

* This library is still kinda bleh-ish/janky.. if zoomed in and you click anywhere else other than one of the unclustered pins, it re-clusters. Just what this library seems to do, even on it's demo page.
* https://bugzilla.mozilla.org/show_bug.cgi?id=896649
* :shipit: