regen_doc.sh: Add optional parameter to customize docker execution

The osmo-nitb-master image can run not only osmo-nitb, but also
osmo-bsc_nat. In that case we can't use the default command from
Dockerfile, but should provide our own. This argument makes it possible
to do so.

Change-Id: I52c3cb2cdcfb143e71ac2c1aa40bb466e41a0f5c
Related: OS#1700

scripts/regen_doc.sh

@@ -6,6 +6,7 @@ NAME="$1"
 PORT="$2"
 COUNTERFILE="$3"
 VTYFILE="$4"
+DOCKER_EXTRA="$5"
 
 IMAGE_SUFFIX="${IMAGE_SUFFIX:-master}"
 if [ -z "$OSMO_INTERACT_VTY" ]; then
@@ -23,7 +24,8 @@ container_create() {
 
 	docker run --rm --network ${NET_NAME} --ip ${IP_ADDR} \
 		--name ${BUILD_TAG}-${CONTAINERNAME} -d \
-		${REPO_USER}/${CONTAINERNAME}
+		${REPO_USER}/${CONTAINERNAME} \
+		${DOCKER_EXTRA}
 
 
 }