BUG/MINOR: swagger: fix swagger version in CI too

Author: mjuraga

.gitlab-ci.yml

@@ -22,7 +22,7 @@ diff:
     - branches
   script:
     #- apk add make curl bash jq
-    - SWAGGER_VERSION=$(curl -s https://raw.githubusercontent.com/haproxytech/client-native/master/Makefile | grep SWAGGER_VERSION -m 1 | awk -F"=" '{print $2}')
+    - SWAGGER_VERSION=v0.23.0
     - wget -q "https://github.com/go-swagger/go-swagger/releases/download/${SWAGGER_VERSION}/swagger_linux_amd64" -O /usr/local/bin/swagger && chmod +x /usr/local/bin/swagger
     - make generate-native
     - test -z "$(git diff 2> /dev/null)" || exit "Specification is not generated, issue \`make generate\` and commit the result"