If multiple clouds are setup and those clouds have the same ssh key_name, they will get overwritten.

Steps to reproduce.

1. Setup Two EC2 clouds
2. Create the same ssh key_name for both clouds
3. Give the clouds different key_materials
4. Upon a refresh from AWS, the keys will have been overwritten by the last key in the database

This is because the code to check for key materials during the download from AWS does not take into account the cloud_context.