Connection not closed on rollback error

Hi,

Seems like there is any issue where connetions aren't properly closed when the rollback throws an exception.
https://github.com/aio-libs/aioodbc/blob/62069a2ecbbc284af75a5d6cf91a1fc4a505f20b/aioodbc/connection.py#L250-L252

An example is when the original query throws:
[08S01] [Microsoft][ODBC Driver 17 for SQL Server]TCP Provider: An existing connection was forcibly closed by the remote host.

Then the rollback will also fail with the same exception and the connection won't be closed.