Fix KeyError in non-existent field
Fix KeyError in non-existent field

In some cases, an validation error in the importer can add error
conditions to a field that may not exist in the row data. These need a
default to avoid key errors.

RickMohr/otm-core,maurizi/otm-core,clever-crow-consulting/otm-core,recklessromeo/otm-core,recklessromeo/otm-core,RickMohr/otm-core,clever-crow-consulting/otm-core,clever-crow-consulting/otm-core,RickMohr/otm-core,maurizi/otm-core,clever-crow-consulting/otm-core,recklessromeo/otm-core,RickMohr/otm-core,maurizi/otm-core,maurizi/otm-core,recklessromeo/otm-core