Fix: Import HashMap instead of Map
Fix: Import HashMap instead of Map

I didn't catch that when merging PR #217.
CI should have catched it, but we actually never ran CI for examples.

Signed-off-by: Matthias Beyer <1d6e1cf70ec6f9ab28d3ea4b27a49a77654d370e@beyermatthias.de>
Fixes: be82af2 ("Rename MapImpl to Map")
Fixes: 0d3a5c3 ("Merge pull request #217 from dlo9/master")

mehcode/config-rs