Removes overly strict validation.

[bmcniel]

Two different triggers for two different lambda that use the same bucket/event are legal as long as the prefix/suffix differ between the two triggers.

s3:
  on-new-upload:
    bucket: ref://receiptUploadBucket
    notifications:
      new-upload:
        lambda: new-upload-queue
        events:
          - s3:ObjectCreated:Put
        key_filters:
          prefix: 'v1/'
      new-upload-v2:
        lambda: new-upload-queue-v2
        events:
          - s3:ObjectCreated:Put
        key_filters:
          prefix: 'v2/'

The above should work as it can be configured by hand. However it fails due to the removed check. Enforcing uniqueness on filter criteria should be enough.

[jorgebastida]

Yup, had the same issue few days ago.