VPP version: 19.04-release

During full performance tests for CSIT report 19.04 we found out that ip4 jumbo frames (9000B) are dropped in case of tests with memif - show error reports ip4-input: ip4 length > l2 length.

observed on:

• 3n-skx system: 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-s1-s6-t7
• 2n-skx system: https://logs.fd.io/production/vex-yul-rot-jenkins-1/csit-vpp-perf-verify-1904-2n-skx/58/archives/log.html.gz#s1-s1-s1-s1-s4-t7
• tests on 3n-hsw are still ongoing, we will update information here when tests are finished