Revert "[#4468] libtool <= 2.2 doesn't have LT_INIT macro so AC_PROG_LIBTOOL...

Revert "[#4468] libtool <= 2.2 doesn't have LT_INIT macro so AC_PROG_LIBTOOL should be used instead."

This reverts commit 590c609e.

Wrong authorship attribution. This was the work of
Marat Radchenko <marat@slonopotamus.org>

sflphone-client-gnome/configure.ac

 AC_INIT([SFLphone],[0.9.11],[sflphoneteam@savoirfairelinux.com],[sflphone-client-gnome])
 AM_CONFIG_HEADER(config.h)
 
+LT_INIT
 GNOME_DOC_INIT
 
 PACKAGE=SFLphone