Clarify license of protobuf-converter

[gunnarmorling]

Hi, the root README file suggests that there should be a dedicated LICENSE file in each of the sub-modules of this repo, stating the license of this particular module. This is missing for the protobuf-converter module, though. Is it licensed under Apache v2, like the Avro converter? Thanks for clarifying!

// CC @rhauch.

[curtisr7]

Any updates? The same problem also exists with the protobuf-serializer[1] module.

[1]https://github.com/confluentinc/schema-registry/tree/master/protobuf-serializer/src/main/java/io/confluent/kafka/serializers/protobuf

[curtisr7]

@rayokota - is the license on the protobuf serializer files[1] wrong, or working as designed? If wrong I'd be glad to open a PR

[1] https://github.com/confluentinc/schema-registry/blob/master/protobuf-serializer/src/main/java/io/confluent/kafka/serializers/protobuf/KafkaProtobufDeserializer.java#L2

[rayokota]

I've been told these are Confluent Community License for now.

[curtisr7]

@rayokota @ewencp is there some sort of a miscommunication here? The docs[1] state that the client libs are apache 2.0 licensed and that's what I'm wanting to get fixed.

[1] https://github.com/confluentinc/schema-registry#license

[rayokota]

@curtisr7 I updated the README

[mproch]

@rayokota I don't think updating README is enough. E.g. in pom both licences are mentioned which is quite misleading.

Tools like sbt-license-report are also getting it wrong: Apache,Apache License 2.0 (http://www.apache.org/licenses/LICENSE-2.0.html),io.confluent # kafka-json-schema-provider # 7.2.0,

I understand your reasons for changing some of the licences, but the way it's handled/declared now is really messy...