Requires gettext for client package

libvirt-guests invokes functions in gettext.sh, so we need to
require gettext package in spec file.

Demo with the fix:
% rpm -q gettext
package gettext is not installed

% rpm -ivh libvirt-client-0.8.8-1.fc14.x86_64.rpm
error: Failed dependencies:
	gettext is needed by libvirt-client-0.8.8-1.fc14.x86_64

* libvirt.spec.in

libvirt.spec.in

@@ -416,6 +416,8 @@ Requires: ncurses
 # So remote clients can access libvirt over SSH tunnel
 # (client invokes 'nc' against the UNIX socket on the server)
 Requires: nc
+# Needed by libvirt-guests init script.
+Requires: gettext
 %if %{with_sasl}
 Requires: cyrus-sasl
 # Not technically required, but makes 'out-of-box' config