doc: display the verbosity argument on log

Without this information, it is easy to imagine the TRACE variable was not correctly set.

templates/gitlab-ci-docker.yml

@@ -617,7 +617,7 @@ stages:
       kaniko_registry_mirror_option="--registry-mirror $(echo ${DOCKER_REGISTRY_MIRROR} | sed "s|^https*://||")"
     fi
     log_info "Build & deploy image $docker_image"
-    log_info "Kaniko command: /kaniko/executor --context $(docker_context_path) --dockerfile $DOCKER_FILE --destination $docker_image ${kaniko_cache_args} $kaniko_registry_mirror_option $DOCKER_METADATA $DOCKER_BUILD_ARGS $*"
+    log_info "Kaniko command: /kaniko/executor ${TRACE+--verbosity debug} --context $(docker_context_path) --dockerfile $DOCKER_FILE --destination $docker_image ${kaniko_cache_args} $kaniko_registry_mirror_option $DOCKER_METADATA $DOCKER_BUILD_ARGS $*"
     # shellcheck disable=SC2086
     /kaniko/executor ${TRACE+--verbosity debug} --context "$(docker_context_path)" --dockerfile "$DOCKER_FILE" --destination "$docker_image" ${kaniko_cache_args} $kaniko_registry_mirror_option $DOCKER_METADATA $DOCKER_BUILD_ARGS "$@"
   }