Merge pull request #668 from fennecus-z/cleanup-replace-stringbuffer-with-stringbuilder

[codestyle] Replace the synchronized class StringBuffer by an unsynchronized one such as StringBuilder.

xwiki-platform-core/xwiki-platform-xar/xwiki-platform-xar-model/src/main/java/org/xwiki/xar/internal/property/ListXarObjectPropertySerializer.java

@@ -49,7 +49,7 @@ public class ListXarObjectPropertySerializer implements XarObjectPropertySeriali
     @Override
     public Object read(XMLStreamReader reader) throws XMLStreamException
     {
-        StringBuffer content = new StringBuffer();
+        StringBuilder content = new StringBuilder();
 
         for (int eventType = reader.next(); eventType != XMLStreamConstants.END_ELEMENT; eventType = reader.next()) {
             if (eventType == XMLStreamConstants.CHARACTERS || eventType == XMLStreamConstants.CDATA