Add handler for exceptions on thread update related to cookies block (see also #258)

src/mibew/libs/classes/Mibew/RequestProcessor/AbstractProcessor.php

@@ -240,6 +240,9 @@ abstract class AbstractProcessor
                     return $this->buildSyncResponses($this->responses);
                 }
             }
+        } catch (\Exception $e) {
+            // Looks like a try to use chat with blocked cookies or something, return 403
+                return new Response('Update forbidden', Response::HTTP_FORBIDDEN);
         } catch (\Exception $e) {
             // Something went wrong. Trigger error event
             $vars = array('exception' => $e);