Ensure presence of kali-linux-firmware on netinst image

Fixes #36

kali-config/installer-netinst/packages

@@ -4,19 +4,6 @@
 # This variant is not meant to be used with live-build but only with
 # simple-cdd and thus ./build.sh --installer --variant netinst
 
-# We still put kali-linux-core because it's really small
-kali-linux-core
-# And we want firmwares
-bluez-firmware
-firmware-amd-graphics
-firmware-atheros
-firmware-brcm80211
-firmware-intel-sound
-firmware-iwlwifi
-firmware-libertas
-firmware-linux
-firmware-misc-nonfree
-firmware-realtek
-firmware-sof-signed
-firmware-ti-connectivity
-firmware-zd1211
+# We still put kali-linux-firmware because we want firmware to be
+# in the ISO for use by the installer
+kali-linux-firmware