VPP version: 19.04-release

During full performance tests for CSIT report 19.04 we found out that IP4 IPSEC tunnel drops all jumbo frames (9000B) - show error reports esp4-encrypt-tun: chained buffers (packet dropped).

• MTU of the physical interface where the IPSEC tunnel is created on is set to 9200
• ispec interface link speed is reported as unknown; we tried to set MTU for packet as well as ip4 on ipsec interface to 9200 but it didn't help
• observed on 3n-skx system for SW crypto device: https://logs.fd.io/production/vex-yul-rot-jenkins-1/csit-vpp-perf-verify-1904-3n-skx/31/archives/log.html.gz#s1-s1-s1-s2-s1-t7
• tests on 3n-hsw (including HW as well as SW crypto device) still ongoing, we will update information here when tests are finished