xs-extra: add lwt to xapi-idl's dependencies
xs-extra: add lwt to xapi-idl's dependencies

It's used for building the binary in misc

Signed-off-by: Pau Ruiz Safont <9c4aad32b049b39a74875643d7fe76c19fd4f9a1@citrix.com>

xapi-project/xs-opam