librdkafka v1.2.2 release

v1.2.2 fixes the producer performance regression introduced in v1.2.1 which may affect high-throughput producer applications.

Fixes

• Fix producer insert msgq regression in v1.2.1 (#2450).
• Upgrade builtin lz4 to 1.9.2 (CVE-2019-17543, #2598).
• Don't trigger error when broker hostname changes (#2591).
• Less strict message.max.bytes check for individual messages (#993).
• Don't call timespec_get() on OSX (since it was removed in recent XCode) by @maparent .
• configure: add --runstatedir for compatibility with autoconf.
• LZ4 is available from ProduceRequest 0, not 3 (fixes assert in #2480).
• Address 12 code issues identified by Coverity static code analysis.

Enhancements

• Add warnings for inconsistent security configuration.
• Optimizations to hdr histogram (stats) rollover.
• Reorganized examples and added a cleaner consumer example, added minimal C++ producer example.
• Print compression type per message-set when debug=msg

Checksums

Release asset checksums:

• v1.2.2.zip SHA256 7557b37e5133ed4c9b0cbbc3fd721c51be8e934d350d298bd050fcfbc738e551
• v1.2.2.tar.gz SHA256 c5d6eb6ce080431f2996ee7e8e1f4b8f6c61455a1011b922e325e28e88d01b53