fix: SCHWED-3096 Check properly for the variable initialization

docker/run_docker_ost

-#! /bin/bash
+#!/bin/bash
 
 # end when error
 set -e
@@ -7,11 +7,11 @@ image_name=$1
 script_path=$2
 
 if [[ ${#@} -lt 1 ]]; then
-    echo "Usage: (sudo) run_docker_ost <IMAGE_NAME> [<SCRIPT_PATH>]"
+    echo "Usage: run_docker_ost <IMAGE_NAME> [<SCRIPT_PATH>]"
     exit 1
 fi
 
-if [[ ${script_path} -eq "" ]]; then
+if [[ -z ${script_path} ]]; then
     docker run -ti --rm ${image_name}
 else
     abspath=$(readlink -f $script_path)