lint modules/groupadd.py

************* Module salt.modules.groupadd
salt/modules/groupadd.py:184: [C0304(missing-final-newline), ] Final newline missing
salt/modules/groupadd.py:167: [W0702(bare-except), deluser] No exception type(s) specified
Merge pull request #11287 from cvrebert/patch-3

lint modules/groupadd.py