Creating a project with no location gives a fatal error

To reproduce:

• Navigate to /civicrm/vol/#/volunteer/manage/0.
• Fill out some fields, but leave the Location field blank.
• Click Continue or Save and Done. Nothing happens.

Some debugging code shows that volunteerProject.create is failing with:

Mandatory key(s) missing from params array: one of (address, address_id, phone, phone_id, im, im_id, email, email_id)

This appears to be coming from the LocBlock.create that happens early in the volunteerProject.create API. It appears we're creating an empty placeholder for the locBlock which seems wrong. I suspect something has changed in locBlock validation that breaks this already-questionable pattern.