cdc: Don't take storage_proxy as transformer::pre_image_select param
cdc: Don't take storage_proxy as transformer::pre_image_select param

transformer has access to storage_proxy through its _ctx field.

Signed-off-by: Piotr Jastrzebski <2c0eb4a25a7cde333ff2d0860cb06051925fd74f@scylladb.com>

scylladb/scylla,scylladb/scylla,scylladb/scylla,avikivity/scylla,scylladb/scylla,avikivity/scylla,avikivity/scylla