London air quality importer null check and valueforsubject return json array in MapToContainingSubjectField

[arya-hemanshu]

i tried to run recipe on LAQNImporter and got a null pointer exception as in importdatasource, it is only checking whether the list empty or not but would also need to check whether it is null or not.

Another error is in MapToContainingSubjectField where valueForSubject is returning json array rather returning only the string value.

These are fairly small changes.

[borkurdotnet]

@arya-hemanshu is this still an issue?

[lorenaqendro]

@arya-hemanshu what about this? Have you seen this again?

Another error is in MapToContainingSubjectField where valueForSubject is returning json array rather returning only the string value.

this one is solved I guess.

[sassalley]

@arya-hemanshu Have you seen this again?