Fix server list provider to be sane

Change-Id: I8e8da91831ce6e9a3e7f13fc0f3c6a8ab735e98a
Reviewed-on: http://gerrit.dmdirc.com/1967
Reviewed-by: Greg Holmes <greg@dmdirc.com>
Automatic-Compile: DMDirc Build Manager

src/com/dmdirc/addons/serverlists/service/ServerListServiceProvider.java

         if ("getParser".equals(name)) {
             return new ExportedService(ServerListServiceProvider.class, "getParser", this);
         } else {
-            return new ExportedService(null, null);
+            return null;
         }
     }