rawgit is in sunset phase

[Hissvard]

Like pointed out on the site itself, rawgit is currently in its sunset phase - in the process of shutting down in October 2019.
MarkerClusterer is currently using as a default resource to host its custom markers

v3-utility-library/markerclustererplus/src/markerclusterer.js

Line 1639 in 2015e66

MarkerClusterer.IMAGE_PATH = "https://cdn.rawgit.com/googlemaps/js-marker-clusterer/gh-pages/images/m";

so it might be appropriate to switch to something else.

[stephenmcd]

Thanks for the heads up