Bundle warning shown for non-entity processors

Problem/Motivation

When importing items that are not entities, Feeds reports that the configured bundle does not exist. This is because in such situation FeedsProcessor::bundleOptions() returns no options. At the same time though FeedsProcessor::configDefaults() autosets the bundle setting equal to the processor's entity type, which a processor is required to define because of the abstract FeedsProcessor::entityType() method. So this results that there is in fact a bundle setting under the hood.

Proposed resolution

Do not display the warning when the bundle setting is not configurable.

Patch will follow.