extension check fix and verbose flag on non-custom janus_create_gallery

When I merged the upstream extension check with my data_path argument addition, I did not update the extension check arguments to reflect the new data_path argument. This is fixed now.

Also, the openbr custom janus_create_gallery function takes a verbose flag that the non-custom version did not. This became apparent once I implemented the API using the janus_create_gallery function from janus_io.cpp (JANUS_CUSTOM_CREATE_GALLERY flag not set)