build: fix startup script for local execution

startup.sh

@@ -29,11 +29,11 @@ if [ -z $API_PORT ]; then
 fi
 
 if [ -z $MYSQL_HOST ]; then
-  MYSQL_HOST="localhost"
+  MYSQL_HOST="$(prop 'MYSQL_HOST')"
 fi
 
 if [ -z $MYSQL_PORT ]; then
-  MYSQL_PORT=3306
+  MYSQL_PORT=$(prop 'MYSQL_PORT')
 fi
 
 echo "Waiting 10 seconds for database to start.."