Remove duplicate additionalName.

The additionalName is getting serialized twice, which the server
rejects with a 400 error.
diff --git a/src/com/google/wireless/gdata2/contacts/serializer/xml/XmlContactEntryGDataSerializer.java b/src/com/google/wireless/gdata2/contacts/serializer/xml/XmlContactEntryGDataSerializer.java
index 1421a18..2efb158 100644
--- a/src/com/google/wireless/gdata2/contacts/serializer/xml/XmlContactEntryGDataSerializer.java
+++ b/src/com/google/wireless/gdata2/contacts/serializer/xml/XmlContactEntryGDataSerializer.java
@@ -526,8 +526,6 @@
                             name.getAdditionalNameYomi(), XmlNametable.GD_NAME_ADDITIONALNAME);
     serializeNameSubelement(serializer, name.getFamilyName(),
                             name.getFamilyNameYomi(), XmlNametable.GD_NAME_FAMILYNAME);
-    serializeNameSubelement(serializer, name.getAdditionalName(),
-                        name.getAdditionalNameYomi(), XmlNametable.GD_NAME_ADDITIONALNAME);
     serializeNameSubelement(serializer, name.getNamePrefix(),
                         null /* yomi */, XmlNametable.GD_NAME_PREFIX);
     serializeNameSubelement(serializer, name.getNameSuffix(),