title: django-rest-swagger double slash
body: <p>I'm having trouble with django-rest-swagger. I did everything (or I think I did) like in swagger documentation, but when I try to test API via "Try it out!" button, it sends request like this, with double slashes</p>
  
  <blockquote>
    <p>"GET /api//activity/ HTTP/1.1" 404 8388 </p>
  </blockquote>
  
  <p>my_app/urls.py</p>
  
  <pre><code>router = routers.DefaultRouter()
  router.register(r'activity', ActivityViewSet)
  router.register(r'diary', DiaryViewSet)
  router.register(r'discipline', DisciplineViewSet)
  router.register(r'ingredient', IngredientViewSet)
  router.register(r'product', ProductViewSet)
  router.register(r'mealtype', MealTypeViewSet)
  router.register(r'meal', MealViewSet)
  
  urlpatterns = [
      path('docs/', get_swagger_view(title='API')),
  ]
  urlpatterns += router.urls
  </code></pre>
  
  <p>urls.py</p>
  
  <pre><code>urlpatterns = [
      path('admin/', admin.site.urls),
      path('api/', include('diet_app.urls'))
  ]
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/4yZse.png" rel="nofollow noreferrer">How it looks at swagger site</a></p>
  
  <p>What could be the problem?</p>