title: Django creates only one related name of ForeignKey instead of two
body: <p>There is a model:</p>
  
  <pre><code>class Transfer(models.Model):
      when = models.DateTimeField()
      _from = models.ForeignKey(User, related_name="income_transfers")
      to = models.ForeignKey(User, related_name="outcome_transfers"),
      total = models.PositiveIntegerField()
  </code></pre>
  
  <p>There is a use case:</p>
  
  <pre><code>income_transfers_total = sum((x.total for x in _user.income_transfers.all()))
  outcome_transfers_total = sum((x.total for x in _user.outcome_transfers.all()))  # error line
  </code></pre>
  
  <p>Last string returns</p>
  
  <pre><code>'User' object has no attribute 'outcome_transfers'
  </code></pre>
  
  <p>Debugger shows that user object really has only "income_transfers" but not "oucome transfer". Where am I wrong?</p>