mappings: update cluster state with type mapping also for failed indexin...

...g request

When indexing of a document with a type that is not in the mappings fails,
for example because "dynamic": "strict" but doc contains a new field,
then the type is still created on the node that executed the indexing request.
However, the change was never added to the cluster state.
This commit makes sure mapping updates are always added to the cluster state
even if indexing of a document fails.

closes #8650
I like to have a comment like `//expected` in the catch here? And nitpick: move the opening brace up to match the style here...