Fix infinite request spinner when cancelling "Send and Download" (#2721)

We were hiding the spinner at the end of the _handleSendAndDownloadRequestWithEnvironment method. However, we
were exiting early we the user cancel the save dialog (L672).

To prevent that, I've moved the code in a finally block, therefore we make sure that the spinner will be hidden

Closes #2718

packages/insomnia-app/app/ui/containers/app.js

@@ -713,15 +713,15 @@ class App extends PureComponent {
           </div>
         ),
       });
+    } finally {
+      // Unset active response because we just made a new one
+      await App._updateRequestMetaByParentId(requestId, {
+        activeResponseId: null,
+      });
+
+      // Stop loading
+      handleStopLoading(requestId);
     }
-
-    // Unset active response because we just made a new one
-    await App._updateRequestMetaByParentId(requestId, {
-      activeResponseId: null,
-    });
-
-    // Stop loading
-    handleStopLoading(requestId);
   }
 
   async _handleSendRequestWithEnvironment(requestId, environmentId) {