title: Placeholder in django form dropdown field
body: <p>I have a little problem with a dropdown field in django form. I want to add to this field placeholder (or not active first option as placeholder) and some other stuff as no label, class etc.
  I wrote something like this, in my <code>forms.py</code> but now my form is broken - don't save values to database.</p>
  
  <pre><code>from .models import Scenario, ScenarioArea
  from django import forms
  
  class newScenario(forms.ModelForm):
      scenarioArea=forms.ModelChoiceField(label="", queryset=ScenarioArea.objects.values_list("scenarioAreaName", flat=True).distinct(), empty_label=None)
  
  lass Meta:
          model = Scenario
          fields = ['scenarioArea']
  </code></pre>
  
  <p>Every other field type is working, but not this dropdown...
  Could you help me?</p>