contacts: inherit gconf

* it's checking for native gconftool-2 and do_configure may fail with:
  | checking for GCONF... yes
  | checking for gconftool-2... no
  | configure: error: gconftool-2 executable not found in your path - should be installed with GConf
  | NOTE: The following config.log files may provide further information.

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>