fix set_keymap rc.conf

By default /etc/rc.conf seems to have KEYMAP commented out which means any key mapping set during the install will be ignored. This commit makes the installer remove the hash (#) prefix, if present.

installer.sh.in

@@ -299,7 +299,7 @@ set_keymap() {
     if [ -f /etc/vconsole.conf ]; then
         sed -i -e "s|KEYMAP=.*|KEYMAP=$KEYMAP|g" $TARGETDIR/etc/vconsole.conf
     else
-        sed -i -e "s|KEYMAP=.*|KEYMAP=$KEYMAP|g" $TARGETDIR/etc/rc.conf
+        sed -i -e "s|#\?KEYMAP=.*|KEYMAP=$KEYMAP|g" $TARGETDIR/etc/rc.conf
     fi
 }