Kororaa Fix: multiple hazard curve location request WSOD

[chrisdicaprio]

If the user requests more than one location specified by lat lon and those locations are rounded to grid sites (i.e. they are not on the location list) they get WSOD. Also, if a single location is requested, but multiple vs30, they get WSOD

Examples of input:
WSOD:
Locations: blank
Coordinates: -37.2, 175; -37.1, 175.1
vs30: 400
spectral period: PGA
probability of exceedence: 10

WORKS:
Locations: blank
Coordinates: -37.1, 175.1
vs30: 400
spectral period: PGA
probability of exceedence: 10

WORKS:
Locations: blank
Coordinates: -37.2, 175
vs30: 400
spectral period: PGA
probability of exceedence: 10

WSOD:
Locations: blank
Coordinates: -37.2, 175
vs30: 400, 500
spectral period: PGA
probability of exceedence: 10