remove some packages for tiny devices

Some devices (e.g. TP-Link RE450) only have 6 MB available space. That's
not enough to hold all the stuff e.g. ca-certs. So only build
ca-certificates, airtime stats etc. when we have enough flash.

site.mk

@@ -23,10 +23,12 @@ GLUON_SITE_PACKAGES := \
 	gluon-ssid-changer \
 	gluon-web-mesh-vpn-fastd \
 	gluon-web-private-wifi \
-	iwinfo \
+	iwinfo
+
+GLUON_SITE_PACKAGES_standard := \
 	respondd-module-airtime \
 	libustream-wolfssl \
-	ca-certificates
+	ca-bundle
 
 ADD_DRIVERS_X86 := \
 	kmod-8139too \