OWB-968 fix infinite loop in Generics handling of Enums

happens because is illegally defined as 
 Enum<E extends Enum<E>>
which actually contradicts the Java lang spec...


git-svn-id: https://svn.apache.org/repos/asf/openwebbeans/trunk@1600999 13f79535-47bb-0310-9956-ffa450edef68