Update group-query.xsd allow custom tag.

web/group-query.xsd

@@ -34,13 +34,11 @@
 						<xs:documentation>聚合函数count</xs:documentation>
 					</xs:annotation>
 				</xs:element>
-				<!-- 
 				<xs:element name="custom" type="customAggrField">
 					<xs:annotation>
 						<xs:documentation>自定义聚合函数表达式</xs:documentation>
 					</xs:annotation>
 				</xs:element>
-				 -->
 				<xs:element name="group" type="groupField" maxOccurs="unbounded" minOccurs="0">
 					<xs:annotation>
 						<xs:documentation>group by的字段</xs:documentation>