Revert "Force cache bust"

This reverts commit 1833fb380b01f777532b3c06cbfcc2f18d5844ee.
Clear the cache used to match a requested URL

We use a cache key based on the requested domain and path to
match the site load to a database record. When we change the
URL of a site, we need to clear this cache so that future
requests load from the expected place.
Merge pull request #205 from washingtonstateuniversity/bug/clear-site-cache

[PR] Clear the cache used to match a requested URL with a site on settings save