base/init: do not clean RD_* environment variables

modules.d/99base/init

@@ -281,6 +281,8 @@ done
 for i in $(export -p); do
     i=${i#declare -x}
     i=${i#export}
+    # skip RD_ vars
+    [ "$i" != "${i#RD_} ] && continue
     i=${i%%=*}
     [ "$i" = "root" -o "$i" = "PATH" -o "$i" = "HOME" -o "$i" = "TERM" ] || unset $i
 done