WIP: integration_2021_wk41

MR !1273 (merged) : [CI] adding Docker Hub push pipeline
MR !1267 (merged) : Enabled multi-threading for gNB L1 tx
MR !1285 (merged) : [CI] test sa nsa

ci-scripts/yaml_files/fr1_epc_20897/docker-compose.yml

@@ -143,6 +143,7 @@ services:
             TAC: 1
             GW_ID: 1
             REALM: openairinterface.org
+            UE_MTU_IPV4: 1500
         healthcheck:
             test: /bin/bash -c "pgrep oai_spgwc"
             interval: 10s