Server FMU leads to a large number of "unable to find check_server.py" error messages

This issue is related to the large number of "unable to find check_server.py" error messages before check_server.py is created for the first time (it takes some time based on the number of python module to import in run_server.py).

Either we need to package a default check_server.py either we need to add a sleep time to prevent the C code to look for the file as fast as possible.