Fix bug#305: pkt_dname_tolower could read beyond end of buffer or   get into an endless loop, if 0x20 was enabled, and buffers are small   or particular broken packets are received.
Fix bug#305: pkt_dname_tolower could read beyond end of buffer or
  get into an endless loop, if 0x20 was enabled, and buffers are small
  or particular broken packets are received.


git-svn-id: e875384d7a5ebd9b2def38a8354dae1fda8e73bc@2073 be551aaa-1e26-0410-a405-d3ace91eadb9

NLnetLabs/unbound,chantra/unbound,chantra/unbound,NLnetLabs/unbound,NLnetLabs/unbound,chantra/unbound,chantra/unbound,chantra/unbound,NLnetLabs/unbound