The command 'rndc dumpdb -expired' will include expired RRsets in the output, but only for the RBTDB_VIRTUAL time (of 5 minutes). This means that if there is a cache cleaning problem and contents are not cleaned up, the rndc command has little diagnostic value. Fix this by including all RRsets in the dumpdb output if the '-expired' flag is set.
(cherry picked from commit 930ba2c9)
Closes #3462 (closed)