Empty software version fails quickstatements

[fnielsen]

Describe the bug Empty software version fails quickstatements

To Reproduce

1. Go to https://scholia.toolforge.org/doi/10.21338/NSD-ESS10-2020

Generates

        CREATE
    LAST    P31 Q191067
    LAST    Len "European Social Survey (ESS), Round 10 - 2020"
    LAST    P348    ""
    LAST    P356    "10.21338/NSD-ESS10-2020"
    LAST    P577    +2022-01-01T00:00:00Z/9
    LAST    P856    "https://ess-search.nsd.no/en/study/172ac431-2a06-41df-9dab-c1fd8f3877e7"
    LAST    P1476   en:"European Social Survey (ESS), Round 10 - 2020"
    LAST    P2093   "European Social Survey ERIC (ESS ERIC)"    P1545   "1"

where https://www.wikidata.org/wiki/Property:P348 (software version) is empty.

Expected behavior The line with an empty software version should not be generated.

Additional context Perhaps an error in https://github.com/citation-js/citation-js? Or our missing update?

[egonw]

cc @larsgw