Trying to associate an already-associated ElasticIP was failing.
This is however supported by the `boto` method that is used
under the hood, `associate_address`:
To quote `boto` documentation:
```
This option to allow an Elastic IP address that is already
associated with another networkinterface or instance to be
re-associated with the specified instance or interface.
```
This defaults to False, both per backwards-compatibility
and to mirror the boto default value.
Fixes#27385
d332367018