Correct default date format

`strictDateOptionalDate` => `strictDateOptionalTime`

docs/reference/migration/migrate_2_0.asciidoc

@@ -302,7 +302,7 @@ Meta fields can no longer be specified within a document. They should be specifi
 via the API.  For example, instead of adding a field `_parent` within a document,
 use the `parent` url parameter when indexing that document.
 
-==== Default date format now is `strictDateOptionalDate`
+==== Default date format now is `strictDateOptionalTime`
 
 Instead of `dateOptionalTime` the new default date format now is `strictDateOptionalTime`,
 which is more strict in parsing dates. This means, that dates now need to have a four digit year,
@@ -796,4 +796,4 @@ For the record, official plugins which can use this new simplified form are:
 
 Fields used in alias filters no longer have to exist in the mapping upon alias creation time. Alias filters are now
 parsed at request time and then the fields in filters are resolved from the mapping, whereas before alias filters were
-parsed at alias creation time and the parsed form was kept around in memory.
+parsed at alias creation time and the parsed form was kept around in memory.