Enable the Tor Browser's font fingerprinting protection.

Sadly this was missed so we won't have it in Tails 2.0.

Fix-committed: #11000

config/chroot_local-includes/usr/local/bin/tor-browser

@@ -57,6 +57,9 @@ start_browser() {
 
     unset SESSION_MANAGER
 
+    export FONTCONFIG_PATH="${TBB_INSTALL}/TorBrowser/Data/fontconfig"
+    export FONTCONFIG_FILE="fonts.conf"
+
     exec_firefox -allow-remote --class "Tor Browser" -profile "${PROFILE}" "${@}"
 }