find_bad prevent attribute error when NULLs are in the database

The following error occurred trying to print out details about a job.
```
File "slurmfixer.py", line 300, in
main()
File "slurmfixer.py", line 294, in main
parsed_args.func()
File "slurmfixer.py", line 137, in find_bad
str(job['state']), job['job_name'])
File "slurmfixer.py", line 144, in print_bad_job_line
print(job_id.ljust(10), start.ljust(20), account.ljust(12), state.ljust(5), user_id.ljust(10), job_name)
AttributeError: 'NoneType' object has no attribute 'ljust'
```
The job in question had an unexpected NULL value for account.