##### SUMMARY

The merge of #45507 broke `update_password="on_create"` on Alpine Linux with the shadow package installed.

This does not work anymore
```yml
  - name: add users                                                                                                                                                                                                                                  
    user:
      name: "{{ item.name }}"
      comment: "{ item.comment }}"
      shell: "/bin/zsh"
      password: '*'
      update_password: on_create
   with_items:
    ....
```

After the PR, all users that have a password that is not '*' will get their password changed.

Reverting bf3e397ea7922e8bd8b8ffbc05d1aede0317d119, makes 'update_password: on_create' work as expected again.

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
<!--- Write the short name of the module, plugin, task or feature below, use your best guess if unsure -->

lib/ansible/modules/system/user.py

##### ANSIBLE VERSION
<!--- Paste verbatim output from "ansible --version" between quotes -->
```paste below
2.8.7
```

##### CONFIGURATION
<!--- Paste verbatim output from "ansible-config dump --only-changed" between quotes -->
```paste below

```

##### OS / ENVIRONMENT
<!--- Provide all relevant information below, e.g. target OS versions, network device firmware, etc. -->

Alpine Linux

##### STEPS TO REPRODUCE
<!--- Describe exactly how to reproduce the problem, using a minimal test-case -->

<!--- Paste example playbooks or commands between quotes below -->
```yaml
  - name: add users                                                                                                                                                                                                                                  
    user:
      name: "{{ item.name }}"
      comment: "{ item.comment }}"
      shell: "/bin/zsh"
      password: '*'
      update_password: on_create
```

<!--- HINT: You can paste gist.github.com links for larger files -->

##### EXPECTED RESULTS
<!--- Describe what you expected to happen when running the steps above -->

Users that are not created does not get their password changed.

##### ACTUAL RESULTS
<!--- Describe what actually happened. If possible run with extra verbosity (-vvvv) -->

<!--- Paste verbatim command output between quotes -->
```paste below
Password "hash" changed to '*'
```

if self.shell is not None and info[6] != self.shell:
            cmd.append('-s')
            cmd.append(self.shell)
        if self.login_class is not None:
            
            user_login_class = None
            userinfo_cmd = [self.module.get_bin_path('userinfo', True), self.name]
            (rc, out, err) = self.execute_command(userinfo_cmd, obey_checkmode=False)
            for line in out.splitlines():
                tokens = line.split()
                if tokens[0] == 'class' and len(tokens) == 2:
                    user_login_class = tokens[1]
            
            if self.login_class != user_login_class:
                cmd.append('-L')
                cmd.append(self.login_class)
        if self.password_lock and not info[1].startswith('*'):
            cmd.append('-Z')
        elif self.password_lock is False and info[1].startswith('*'):
            cmd.append('-U')
        if self.update_password == 'always' and self.password is not None \
                and self.password != '*' and info[1] != self.password:
            cmd.append('-p')
            cmd.append(self.password)
        
        if len(cmd) == 1:
            return (None, '', '')
        cmd.append(self.name)
        return self.execute_command(cmd)
class NetBSDUser(User):