glib-networking: add missing host-intltool dependency

Fixes the following problem:

checking whether NLS is requested... yes
checking for intltool >= 0.35.0... ./configure: line 12323: intltool-update: command not found
 found
configure: error: Your intltool is too old.  You need intltool 0.35.0 or later.
make: *** [/home/test/test/output/build/glib-networking-2.30.2/.stamp_configured] Error 1

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>