Revert GoogleBusinessProvider "client_id" parameter back to just "client"

This reverts commit 532345bbd41221d2460591844dfffb04194c662a and a918a19d148911ce8d686246f789285060b579a5.

See: https://github.com/willdurand/Geocoder/commit/a918a19d148911ce8d686246f789285060b579a5