connman: make dependency on awk explicit

pkgs/tools/networking/connman/default.nix

···
-{ stdenv, fetchurl, pkgconfig, openconnect, file,
+{ stdenv, fetchurl, pkgconfig, openconnect, file, gawk,
   openvpn, vpnc, glib, dbus, iptables, gnutls, polkit,
   wpa_supplicant, readline6, pptp, ppp }:
 
···
                   openvpn vpnc glib dbus iptables gnutls
                   wpa_supplicant readline6 pptp ppp ];
 
-  nativeBuildInputs = [ pkgconfig file ];
+  nativeBuildInputs = [ pkgconfig file gawk ];
 
   preConfigure = ''
     export WPASUPPLICANT=${wpa_supplicant}/sbin/wpa_supplicant
     export PPPD=${ppp}/sbin/pppd
+    export AWK=${gawk}/bin/gawk
     sed -i "s/\/usr\/bin\/file/file/g" ./configure
   '';