firefox: fixed build by removing postmake hook that is calling 'firefox -register' (see note)

Note:

Seems that while calling 'firefox -register' it tries to establish a network
connection, which won't work of course in a unconfigured sandbox. Because it
builds without "registering" I am removing the crap.

www/firefox/firefox.conf

@@ -56,10 +56,6 @@ fi
 
 hook_add preconf  4 "firefox_config"
 
-# this annoying javascript (tm) based whatever component registration
-hook_add postmake 6 "$root$bindir/firefox -register"
-
-# work around for version 2.0
 # Merged from T2
 var_append GCC_WRAPPER_INSERT ' ' "-c?:-L`pkgprefix libdir libx11` -lX11 -lXrender"