Delete cache entry in close_connection
Delete cache entry in close_connection

This is to prevent redundant attempts to cancel the query in the
backend with an old cache entry.

Signed-off-by: Byron Ruth <e9d71f5ee7c92d6dc9e92ffdad17b8bd49418f98@devel.io>

murphyke/avocado,murphyke/avocado,murphyke/avocado,murphyke/avocado