[BUG] pdbedit.list verbose=True fails when Samba has verbose logging enabled and users are present in pdb

Description
pdbedit.list verbose=True fails with:

[ERROR   ] An un-handled exception was caught by salt's global exception handler:
KeyError: 'unix username'
Traceback (most recent call last):
  File "/usr/bin/salt-call", line 11, in <module>
    load_entry_point('salt==3001.1', 'console_scripts', 'salt-call')()
  File "/usr/lib/python3/dist-packages/salt/scripts.py", line 445, in salt_call
    client.run()
  File "/usr/lib/python3/dist-packages/salt/cli/call.py", line 58, in run
    caller.run()
  File "/usr/lib/python3/dist-packages/salt/cli/caller.py", line 121, in run
    ret = self.call()
  File "/usr/lib/python3/dist-packages/salt/cli/caller.py", line 228, in call
    ret["return"] = self.minion.executors[fname](
  File "/usr/lib/python3/dist-packages/salt/executors/direct_call.py", line 12, in execute
    return func(*args, **kwargs)
  File "/usr/lib/python3/dist-packages/salt/modules/pdbedit.py", line 122, in list_users
    users[user_data["unix username"]] = user_data
KeyError: 'unix username'
Traceback (most recent call last):
  File "/usr/bin/salt-call", line 11, in <module>
    load_entry_point('salt==3001.1', 'console_scripts', 'salt-call')()
  File "/usr/lib/python3/dist-packages/salt/scripts.py", line 445, in salt_call
    client.run()
  File "/usr/lib/python3/dist-packages/salt/cli/call.py", line 58, in run
    caller.run()
  File "/usr/lib/python3/dist-packages/salt/cli/caller.py", line 121, in run
    ret = self.call()
  File "/usr/lib/python3/dist-packages/salt/cli/caller.py", line 228, in call
    ret["return"] = self.minion.executors[fname](
  File "/usr/lib/python3/dist-packages/salt/executors/direct_call.py", line 12, in execute
    return func(*args, **kwargs)
  File "/usr/lib/python3/dist-packages/salt/modules/pdbedit.py", line 122, in list_users
    users[user_data["unix username"]] = user_data
KeyError: 'unix username'

# pdbedit --list --verbose 
tdbsam_open: successfully opened /var/lib/samba/private/passdb.tdb

pdbedit module is matching lines with ':' symbol:

{'tdbsam_open': 'successfully opened /var/lib/samba/private/passdb.tdb'}

Setup
ii samba 2:4.11.6+dfsg-0ubuntu1.4 amd64 SMB/CIFS file, print, and login server for Unix

Steps to Reproduce the behavior

1. Add to smb.conf the following line:
   log level = passdb:4
   (level 4 or anything higher will break it)
2. salt-call pdbedit.list verbose=True

Expected behavior
Clean exit with no users listed.

Versions Report

Salt Version:
           Salt: 3001.1
 
Dependency Versions:
           cffi: Not Installed
       cherrypy: Not Installed
       dateutil: 2.7.3
      docker-py: Not Installed
          gitdb: Not Installed
      gitpython: Not Installed
         Jinja2: 2.10.1
        libgit2: Not Installed
       M2Crypto: Not Installed
           Mako: Not Installed
   msgpack-pure: Not Installed
 msgpack-python: 0.6.2
   mysql-python: 1.4.4
      pycparser: Not Installed
       pycrypto: 2.6.1
   pycryptodome: 3.6.1
         pygit2: Not Installed
         Python: 3.8.5 (default, Jul 28 2020, 12:59:40)
   python-gnupg: 0.4.5
         PyYAML: 5.3.1
          PyZMQ: 18.1.1
          smmap: Not Installed
        timelib: Not Installed
        Tornado: 4.5.3
            ZMQ: 4.3.2
 
System Versions:
           dist: ubuntu 20.04 focal
         locale: utf-8
        machine: x86_64
        release: 5.4.0-42-lowlatency
         system: Linux
        version: Ubuntu 20.04 focal

Start with salt/modules/pdbedit.py, especially the list_users entry point shown in the traceback, and reproduce the failure with salt-call pdbedit.list verbose=True after enabling Samba passdb logging. Trace how verbose output lines are parsed; done means logging-only output no longer causes a KeyError and the command exits cleanly with no users listed.