device type expression in mqtt extension config is not required 7781297 (#1402)

* Fix NPE in netty-mqtt client on puback

* Fix gateway mqtt extension configuration - filter is not required

* device type expression in mqtt extension config is not required

ui/src/app/extension/extensions-forms/extension-form-mqtt.tpl.html

@@ -241,14 +241,14 @@
                                                                                 </md-input-container>
                                                                                 <md-input-container ng-if="map.converter.typeExp == 'deviceTypeJsonExpression'" flex="60" class="md-block" md-is-error="theForm['mqttJsonTypeExp_' + brokerIndex + mapIndex].$touched && theForm['mqttJsonTypeExp_' + brokerIndex + mapIndex].$invalid">
                                                                                     <label translate>extension.json-type-expression</label>
-                                                                                    <input required name="mqttJsonTypeExp_{{brokerIndex}}{{mapIndex}}" ng-model="map.converter.deviceTypeJsonExpression">
+                                                                                    <input name="mqttJsonTypeExp_{{brokerIndex}}{{mapIndex}}" ng-model="map.converter.deviceTypeJsonExpression">
                                                                                     <div ng-messages="theForm['mqttJsonTypeExp_' + brokerIndex + mapIndex].$error">
                                                                                         <div translate ng-message="required">extension.field-required</div>
                                                                                     </div>
                                                                                 </md-input-container>
                                                                                 <md-input-container ng-if="map.converter.typeExp == 'deviceTypeTopicExpression'" flex="60" class="md-block" md-is-error="theForm['mqttTopicTypeExp_' + brokerIndex + mapIndex].$touched && theForm['mqttTopicTypeExp_' + brokerIndex + mapIndex].$invalid">
                                                                                     <label translate>extension.topic-type-expression</label>
-                                                                                    <input required name="mqttTopicTypeExp_{{brokerIndex}}{{mapIndex}}" ng-model="map.converter.deviceTypeTopicExpression">
+                                                                                    <input name="mqttTopicTypeExp_{{brokerIndex}}{{mapIndex}}" ng-model="map.converter.deviceTypeTopicExpression">
                                                                                     <div ng-messages="theForm['mqttTopicTypeExp_' + brokerIndex + mapIndex].$error">
                                                                                         <div translate ng-message="required">extension.field-required</div>
                                                                                     </div>