ag_any: respect target root also when the file does not exist in the original root

[boo#903747](https://bugzilla.opensuse.org/show_bug.cgi?id=903747).

Targeted for SLE12 because it is a trivial bugfix.
The reported bug would only be fixed if the fix is applied to the inst-sys (as a DUD or as a DVD respin).
maybe just properly set it like
```
export LD_LIBRARY_PATH="\
$ROOT/liby2util-r/$LIB:\
$ROOT/libycp/$LIB:\
$ROOT/liby2/$LIB:\
$ROOT/libscr/$LIB:\
$ROOT/wfm/$LIB:\
$ROOT/scr/$LIB"
```