Fixed minor typos in ims_charging-documentation

modules/ims_charging/doc/ims_charging.xml

@@ -41,6 +41,12 @@
 
       <holder>Smile Communications</holder>
     </copyright>
+    <copyright>
+      <year>2013</year>
+
+      <holder>ng-voice GmbH</holder>
+    </copyright>
+
   </bookinfo>
 
   <toc/>