[package] base-files: skip LEDs handled by rssileds in led init-script

[package] base-files: skip LEDs handled by rssileds in led init-script

Without this, /etc/init.d/led will try to set the non-existing 'rssi' trigger.
This doesn't harm as the kernel will refuse this setting, but it outputs some
ugly log-lines:
Jun 24 10:15:19 OpenWrt user.info sysinit: setting up led RSSILOW
Jun 24 10:15:19 OpenWrt user.info sysinit: sh: write error: Invalid argument
...

In order to avoid this, skip LEDs with trigger = "rssi" in /etc/init.d/led

Signed-off-by: Daniel Golle <dgolle@allnet.de>
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@33717 3c298f89-4303-0410-b956-a3cf2f4a3e73