hubzilla compatibility at least until next hz release

Code/Daemon/Notifier.php

@@ -755,6 +755,11 @@ class Notifier implements DaemonInterface
                 continue;
             }
 
+            // @FIXME do not send Add/Collection activities to Hubzilla until they support them.
+            if (in_array($target_item['verb'], ['Add', 'Remove']) && $hub['hubloc_network'] === 'zot6') {
+                continue;
+            }
+
             $packet = Libzot::build_packet(
                 self::$channel,
                 self::$packet_type,