title: drf-yasg provides wrong paths to URIs
body: <p>In my application I need to have multiple Swagger pages with grouped endpoints for multiple clients.</p>
  
  <p>One of my clients (paths) supplies mobile app API, another supplies web client API. URL patterns are kept in 2 different <code>urls.py</code> accordingly.</p>
  
  <p>I'm using <a href="https://drf-yasg.readthedocs.io/en/stable/index.html" rel="noreferrer">drf-yasg</a> to generate schema for my API.</p>
  
  <p>To generate <code>swagger</code> specification for those I'm initializing 2 separate <code>schema_views</code> for each <code>urls.py</code> file like this:</p>
  
  <pre><code>from api_mobile.urls import urlpatterns as mobile_patterns
  from api_web.urls import urlpatterns as web_patterns
  
  mobile_schema_view = get_schema_view(
  openapi.Info(
      title="Mobile API",
      default_version='v3',
  ),
  public=True,
  permission_classes=(permissions.AllowAny,),
  patterns=mobile_patterns,
  )
  
  web_schema_view = get_schema_view(
      openapi.Info(
          title="Web API",
          default_version='v1',
      ),
      public=True,
      permission_classes=(permissions.AllowAny,),
      patterns=web_patterns,
  )
  
  urlpatterns = [
      path(
          'api/mobile/docs',
          mobile_schema_view.with_ui('swagger', cache_timeout=0),
          name='mobile-schema-ui'
      ),
      path(
          'api/web/docs',
          web_schema_view.with_ui('swagger', cache_timeout=0),
          name='web-schema-ui'
      ),
  
      path('api/mobile/v3/', include('api_mobile.urls'), name='mobile_urls'),
      path('api/web/v1/', include('api_web.urls'), name='web_urls'),
      ...
  ]
  </code></pre>
  
  <p>Where <code>mobile_patterns</code> and <code>web_patterns</code> are just a list of url patterns.</p>
  
  <p>If I open <code>http://localhost:8000/api/mobile/docs</code> or <code>http://localhost:8000/api/web/docs</code> I do see correctly generated schema for both lists of patterns, yet if I try to do a request directly from <code>swagger</code> specification page all endpoints return <code>404</code> error – they all try to do a request to non-existing url pattern without providing full path to endpoint.</p>
  
  <p>So if I do a request to any view from <code>mobile</code> endpoints swagger tries to do a request at</p>
  
  <p><code>http://localhost:8000/some_mobile_url/</code> instead of <code>http://localhost:8000/api/mobile/v3/some_mobile_url/</code></p>
  
  <p>And situation is the same for another schema, swagger wrongly requests <code>http://localhost:8000/some_web_url/</code> instead of using full path 
  <code>http://localhost:8000/api/web/v3/some_web_url/</code></p>
  
  <p>Obviously being able to test API directly through <code>swagger</code> is very important so specification itself is not enough in my case.</p>
  
  <p>Is this an issue in me misconfiguring <code>swagger</code> itlesf or should I be somehow providing path to <code>swagger</code> so it prepends full path to each url accordingly?</p>