Possible NPE in XMLRPCCommon.java

```
Looking at the XMLRPCCommon class - setting iXMLRPCSerializer to null will 
throw an NPE. Could do a lazy initialization in the constructor (to null), and 
then do a check in serializeParams() to see if iXMLRPCSerializer is null. If 
so, initialize it to XMLRPCSerializer.

```

Original issue reported on code.google.com by `rsrihar...@gmail.com` on 30 May 2014 at 3:43
