title: Django admin inline has 2 foreign keys to the same model
body: <p>Currently i have the transfer model as followed:</p>
  
  <pre><code>class Transfers(models.Model):
      class Meta:
          db_table = "transfers"
          verbose_name = 'Transfer'
          verbose_name_plural = 'Transfers'
  user = models.ForeignKey("backend.User", null=True, blank=True, related_name='user_transfer', on_delete=models.CASCADE)
  
  to_account = models.ForeignKey("backend.User", null=True, blank=True, related_name='user_transfer_to_account', on_delete=models.SET_NULL)
  </code></pre>
  
  <p>A transfer object need to have from one user transfer to another user so i need to use the same User model</p>
  
  <p>And in my admin.py:</p>
  
  <pre><code>class TransfersInline(admin.StackedInline):
      model = Transfers
  
      can_delete = False
      extra = 0
      max_num=0
  
      form = TransfersAdminForm
  
  class UserAdminCustom(admin.ModelAdmin):
  
      exclude = ('password', 'last_login', 'is_superuser', 'is_staff', 'groups',
                 'user_permissions', 'username', 'first_name', 'last_name', 'is_active', 'date_joined')
  
      inlines = [
          TransfersInline,
      ]
  
      def get_queryset(self, request):
          qs = super(UserAdminCustom, self).get_queryset(request)
          return qs.filter(is_staff=False)
  
      def get_readonly_fields(self, request, obj=None):
          return ('id', 'created', 'modified')
  
  
  admin.site.register(User, UserAdminCustom)
  </code></pre>
  
  <p>In my admin i would like to display transfers inline that the User existed in <code>user</code> field of <code>Transfers</code> model but inline can't have multiple foreign key to the same model:</p>
  
  <pre><code>&lt;class 'backend.admin.TransfersInline'&gt;: (admin.E202) 'backend.Transfers' has more than one ForeignKey to 'backend.User'
  </code></pre>
  
  <p>My question is how do i only make TransfersInline use foreign key from <code>user</code> field instead of <code>to_account</code> field ? (transfer inline will have all the transfers object that the User is in user field )</p>