Fix Rsocket test XML configs for latest Mockito

Author: artembilan

spring-integration-rsocket/src/test/java/org/springframework/integration/rsocket/config/RSocketInboundGatewayParserTests-context.xml

@@ -13,7 +13,8 @@
 	</bean>
 
 	<bean id="rsocketStrategies" class="org.mockito.Mockito" factory-method="mock">
-		<constructor-arg value="org.springframework.messaging.rsocket.RSocketStrategies"/>
+		<constructor-arg value="org.springframework.messaging.rsocket.RSocketStrategies"
+						 type="java.lang.Class"/>
 	</bean>
 
 	<int:channel id="requestChannel"/>