Mapping component bug fix

[lutzb-edje]

This change fixes a bug when importing the Mapping component.

Steps to reproduce the bug:

• In environment A, create a flow with a mapping component and assign any number of fields mapped from Input model -> Output model
• Export the flow from environment A
• Import the flow into environment B
• In environment A, change the mapping lines in any way
• Export the flow again from environment A
• Import the flow again into environment B
• Bug: The mappings from the first export will persist after the import.

This bug was being caused by the existing METL_component_model_setting records not being cleaned up after the import. Also fixed a typo.