Stop requiring explicit bindtype specification for non-scalar references

Stop requiring explicit bindtype specification for non-scalar references

As ilmari correctly pointed out this is not necessary, I am not sure why I
didn't catch this on review...

<ilmari> ribasushi: why does DBIC think every DBD needs speical attrs to bind non-scalar values?
<ilmari> DBD::Pg handles binding arrayrefs autmoatically
<ribasushi> ilmari: at the time this was written DBD::Pg *did not* auto-infer bindtype for arrays, that's a relatively new thing
<ribasushi> ilmari: hmmm... this does not seem to be the case, will dig deeper...