Update provision_slurm.py.j2 to import defaultdict to silence this error

Traceback (most recent call last):
 File "/usr/local/sbin/provision_slurm.py", line 100, in <module>
   mk_slurmuser_batch(usergroup,"default")
 File "/usr/local/sbin/provision_slurm.py", line 67, in mk_slurmuser_batch
   userdict = defaultdict(list)
NameError: global name 'defaultdict' is not defined

roles/provision_slurm/templates/provision_slurm.py.j2

@@ -4,6 +4,7 @@ import traceback
 import os
 import stat
 import subprocess
+from collections import defaultdict
 
 
 class ldapSearchConfig: