fix return value of getSiteData()

[rlr]

r? @pdehaan

[pdehaan]

r+

[pdehaan]

Not sure if we want to republish to npm. The key difference seems to be now if we pass an non-matching domain, we get an empty object back. The old behavior was we'd get undefined back (which could cause errors if we try and access a property of the undefined object).

[rlr]

Yep, we should publish update to npm. I'll do it once I get the repo powers I need.

[k88hudson]

I can publish, let's ping someone about repo access

[rlr]

thank you! @k88hudson