Follow-up fix wrt #4783: prevent too early fail on abstract Map types

[cowtowncoder]

No description provided.

[JooHyukKim]

Should we add test cases for Map's as well?

[cowtowncoder]

If you want to write a test, nothing against that, but also not critical.

I did notice that couple of tests started failing in jackson-datatypes-collections now (for case of attempts to deserialize Guava immutable collections without registering module), fixed. Found via cascading re-build (but there's bit of delay so didn't see last night). :)
Tests were checking fail message which changed slightly (instead of saying no deserializer found complains about missing Creator).