ResourceLoader: make `cacheReport` option false by default

ResourceLoader: make `cacheReport` option false by default

In the three years or so that I have been around, we at Wikimedia have not to
my knowledge used the cache keys to manage the cache of ResourceLoader modules.
Instead, if we want to force a module to rebuild, we simply touch one of its
files. (Though even that is not often required these days.)

Change-Id: Ib62a792e053572f268d4be19a10f99f84c07abc5