sumologicschemaprocessor: possible conflict during attributes aggregation

[sumo-drosiek]

There is possible conflict within attributes aggregation for the following configuration:

processors:
  sumologic_schema:
    aggregate_attributes:
      - attribute: <attribute>
        prefixes:
          - foo_
          - foo2_

and the following attributes:

foo_bar
foo2_bar

Both of them are going to be added as bar to the <attribute>, which results in undefined behavior