fix the run.sh script

without the changes it was failing at first run

run.sh

@@ -1,9 +1,12 @@
 #!/bin/bash
 cd network_inventory
 if [ -f ./.second_run ]; then
+    sleep 2
+    python manage.py makemigrations inventory
     python manage.py makemigrations
     python manage.py migrate
 else
+    python manage.py makemigrations inventory
     python manage.py makemigrations
     python manage.py migrate
     python manage.py loaddata inventory