avoid duplicated rtfree() on default router list change (could cause panic). sync with kame 1.46 -> 1.47.
avoid duplicated rtfree() on default router list change (could cause panic).
sync with kame 1.46 -> 1.47.

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase