Dont trap exceptions at debug level 4

[Alex-developer]

When level 4 is set dont catch errors in flow-runner.py

This will make it easier to see problems

[Alex-developer]

When debug level 4 is set the flow runner will not trap any exceptions thrown in modules. This make sit far easier to find issues

To test. Set the debug level to 4 and then introduce a deliberate exception in a module. Best way is to add something like

a = 5 / 0

in the main module code to force a division by zero error.

When level 4 is set the exception will be in the allsky.log or allskyperiodic.log

When any other level is set the exception will be trapped and reported