Respect <description> within <entry> per beans XSD

Prior to this change, a parsing exception would be thrown if a
<description> element was placed within a <map><entry/></map>
element. The beans XSD has always permitted this arrangement,
but BeanDefinitionParserDelegate did not respect it. The latter now
simply ignores any <description> element, rather than failing.

Issue: SPR-8563

org.springframework.beans/src/main/java/org/springframework/beans/factory/xml/BeanDefinitionParserDelegate.java

@@ -1255,7 +1255,10 @@ public class BeanDefinitionParserDelegate {
 					}
 					else {
 						// Child element is what we're looking for.
-						if (valueEle != null) {
+						if (nodeNameEquals(candidateEle, DESCRIPTION_ELEMENT)) {
+							// the element is a <description> -> ignore it
+						}
+						else if (valueEle != null) {
 							error("<entry> element must not contain more than one value sub-element", entryEle);
 						}
 						else {