fix: Correctly detect configuration for the webrtc-card live provider (#1850)

- Closes #1843

If this breaks something for you, please let me know. As a workaround,
you should manually be able to set it back to what it was with something
like:

```yaml
cameras:
 - camera_entity: camera.office
   webrtc_card:
      url: <frigate camera name>
```

src/card.ts

@@ -411,11 +411,11 @@ class FrigateCard extends LitElement {
               : undefined}
             .deviceRegistryManager=${this._controller.getDeviceRegistryManager()}
           ></frigate-card-views>
-          ${
-            // Keep message rendering to last to show messages that may have been
-            // generated during the render.
-            renderMessage(this._controller.getMessageManager().getMessage())
-          }
+          ${this._controller.getMessageManager().hasMessage()
+            ? // Keep message rendering to last to show messages that may have been
+              // generated during the render.
+              renderMessage(this._controller.getMessageManager().getMessage())
+            : ''}
         </div>
         ${this._renderMenuStatusContainer('bottom')}
         ${this._config?.elements