message: Add a deprecation warning to ./configure
diff: @@ -720,6 +720,10 @@ fi
  echo
  echo ZNC AC_PACKAGE_VERSION configured
  echo
  +echo "The configure script is deprecated and will be removed from ZNC"
  +echo "in some future version. Use either CMake or the convenience wrapper"
  +echo "configure.sh which takes the same parameters as configure."
  +echo
  echo "prefix: $prefix"
  echo "debug: $DEBUG"
  echo "ipv6: $IPV6"
  