Made the destructors of ArchiveJob and RetrieveJob pure virtual

scheduler/ArchiveJob.hpp

@@ -75,7 +75,7 @@ public:
   /**
    * Destructor.
    */
-  ~ArchiveJob() throw();
+  virtual ~ArchiveJob() throw() = 0;
 
   /**
    * Returns the name of the destination tape pool.

scheduler/RetrieveJob.hpp

@@ -76,7 +76,7 @@ public:
   /**
    * Destructor.
    */
-  ~RetrieveJob() throw();
+  virtual ~RetrieveJob() throw() = 0;
 
   /**
    * Indicates that the job was successful