fixup! feat(binding_mqtt): support MQTT URI scheme

Author: JKRhb

lib/src/binding_mqtt/mqtt_extensions.dart

@@ -15,7 +15,6 @@ import '../definitions/security/auto_security_scheme.dart';
 import '../definitions/security/basic_security_scheme.dart';
 import '../definitions/validation/validation_exception.dart';
 import 'constants.dart';
-import 'mqtt_binding_exception.dart';
 
 /// [PrefixMapping] for expanding MQTT Vocabulary terms from compact IRIs.
 final mqttPrefixMapping = PrefixMapping(defaultPrefixValue: mqttContextUri);