[Bugfix] 修改tab -> space, 删除system user的 as default

apps/assets/models.py

@@ -144,7 +144,6 @@ class SystemUser(models.Model):
     protocol = models.CharField(max_length=16, choices=PROTOCOL_CHOICES, default='ssh', verbose_name=_('Protocol'))
     _private_key = models.CharField(max_length=4096, blank=True, verbose_name=_('SSH private key'))
     _public_key = models.CharField(max_length=4096, blank=True, verbose_name=_('SSH public key'))
-    as_default = models.BooleanField(default=False, verbose_name=_('As default'))
     auto_push = models.BooleanField(default=True, verbose_name=_('Auto push'))
     auto_update = models.BooleanField(default=True, verbose_name=_('Auto update pass/key'))
     sudo = models.TextField(max_length=4096, default='/user/bin/whoami', verbose_name=_('Sudo'))
@@ -269,6 +268,7 @@ class AssetGroup(models.Model):
 def get_default_idc():
     return IDC.initial()
 
+
 class Tag(models.Model):
     name = models.CharField(max_length=64, unique=True, verbose_name=_('Name'))
     created_time = models.DateTimeField(auto_now_add=True, verbose_name=_('Create time'))