Setup: Remove debug message for "caches"

Setup: Remove debug message for "caches"

This is currently forcing more object cache interfaces to be constructed
than might be needed in a given request. The configuration for these
interfaces is usually quite straight forward or can be trivially
verified from eval.php.

If we do want to log this, I would recommend doing it from the classes
constructor instead e.g. something like:

  LoggerFactory::getInstance('MessageCache')->debug( get_class( $cache ) );

Bug: T189966
Change-Id: I06dc6dfbdf274bb57e9295b0c757b8d52c02acbe