Deprecate OkHttp 2.x support [SPR-14344]

[spring-projects-issues]

Juergen Hoeller opened SPR-14344 and commented

The current OkHttp 3.3 supersedes OkHttp 2.x in every respect.

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Issue Links:

• OkHttp implementations of ClientHttpRequestFactory / AsyncClientHttpRequestFactory [SPR-12893] #17492 OkHttp implementations of ClientHttpRequestFactory / AsyncClientHttpRequestFactory
• Support for OkHttp 3 [SPR-14024] #18596 Support for OkHttp 3
• Revisit dependency baseline: Jetty 9.4+, OkHttp 3+ [SPR-15038] #19604 Revisit dependency baseline: Jetty 9.4+, OkHttp 3+

Referenced from: commits ccf791b