* Returns TRUE if the `attribute' attribute was found and FALSE
* if such attribute is not present in the `payload', or the `object_size'
* is not sufficient. See the definition of SilcAttribute for the
* Returns TRUE if the `attribute' attribute was found and FALSE
* if such attribute is not present in the `payload', or the `object_size'
* is not sufficient. See the definition of SilcAttribute for the