added check for signed note for shared section

app/Http/Controllers/GuestController.php

@@ -28,7 +28,8 @@ class GuestController extends Controller
 
         $patient = null;
         if($section->note){
-           $patient = $section->note->client;
+            abort_if($section->note->is_signed_by_hcp, 401, 'Note is already signed.');
+            $patient = $section->note->client;
         }else{
             $patient = $section->client;
         }