Use JavaScript instead of Ruby

https://build.spring.io/browse/INT-SI43X-230

Looks like Ruby engine takes some time to start and
`Jsr223InboundChannelAdapterTests` is slow as 3 seconds locally as well

* Change the script to JavaScript and now we have 200 millis

**Cherry-pick to 4.3.x**

spring-integration-scripting/src/test/java/org/springframework/integration/scripting/config/jsr223/Jsr223InboundChannelAdapterTests-context.xml

@@ -13,13 +13,10 @@
 
 	<inbound-channel-adapter channel="inbound-channel-adapter-channel">
 		<poller max-messages-per-poll="1" fixed-delay="100"/>
-		<script:script lang="ruby">
+		<script:script lang="javascript">
 			<![CDATA[
-			require "java"
-			java_import 'java.util.Date'
-
-			Date.new
-			]]>
+					(function(){ return new (Java.type('java.util.Date'))(); })();
+				]]>
 		</script:script>
 		<header name="foo" value="bar"/>
 	</inbound-channel-adapter>