fixup! Improve error handling using a fail-fast approach

Author: JohT

scripts/startNeo4j.sh

@@ -50,7 +50,7 @@ if [ -n "${neo4jNotRunning}" ]; then
 
     # Check if there is already a process that listens to the Neo4j HTTP port
     port_listener_process_id=$( lsof -t -i:"${NEO4J_HTTP_PORT}" -sTCP:LISTEN || true )
-    if [ -z "${port_listener_process_id}" ]; then
+    if [ -n "${port_listener_process_id}" ]; then
         echo "startNeo4j: There is already a process that listens to port ${NEO4J_HTTP_PORT}"
         ps -p "${port_listener_process_id}"
         echo "startNeo4j: Use this command to stop it: kill -9 \$( lsof -t -i:${NEO4J_HTTP_PORT} -sTCP:LISTEN )"