When convertion of xmlrpc argument to type fails, report it as error

src/ejabberd_xmlrpc.erl

@@ -373,6 +373,10 @@ try_do_command(AccessCommands, Auth, Command, AttrL,
 			       "The call provided additional unused "
 				 "arguments:~n~p",
 			       [ExitAtL]);
+      exit:{invalid_arg_type, Arg, Type} ->
+	  build_fault_response(-122,
+			       "Parameter '~p' can't be coerced to type '~p'",
+			       [Arg, Type]);
       Why ->
 	  build_fault_response(-118,
 			       "A problem '~p' occurred executing the "
@@ -472,7 +476,7 @@ format_arg(undefined, binary) -> <<>>;
 format_arg(undefined, string) -> "";
 format_arg(Arg, Format) ->
     ?ERROR_MSG("don't know how to format Arg ~p for format ~p", [Arg, Format]),
-    throw({error_formatting_argument, Arg, Format}).
+    exit({invalid_arg_type, Arg, Format}).
 
 process_unicode_codepoints(Str) ->
     iolist_to_binary(lists:map(fun(X) when X > 255 -> unicode:characters_to_binary([X]);