proxmox_user can't create user on PVE 9 #163 (#194)

* Fixes the bug, originally posted: #163 (comment)

* Added changelog fragement

Author: mikeely

changelogs/fragments/163-proxmox-cant-create-user-bugfix.yml

@@ -0,0 +1,2 @@
+bugfixes:
+  - proxmox_user - added a third case when testing for not-yet-existant user (https://github.com/ansible-collections/community.proxmox/issues/163)

plugins/modules/proxmox_user.py

@@ -143,7 +143,7 @@ def is_user_existing(self, userid):
             user_data = self.proxmox_api.access.users(userid).get()
             return user_data
         except Exception as e:
-            if "does not exist" in str(e).lower() or "not found" in str(e).lower():
+            if "does not exist" in str(e).lower() or "not found" in str(e).lower() or "no such user" in str(e).lower():
                 return False
             else:
                 self.module.fail_json(msg="Unable to retrieve user {0}: {1}".format(userid, e))