Memory leak in georaster driver

[lucafibbi]

In "GeoRasterWrapper::Open" fuction (file georaster_wrapper.cpp) this statment:

    poGRW->poConnection = new OWConnection( papszParam[0],
                                            papszParam[1],
                                            papszParam[2] );

creates the poConnection variable that is never destroyed. This cause that the connection to Oracle database is not closed when the GeoRasterWrapper object is destroyed

[ilucena]

Previously the destroy connection was done on georaster_driver.cpp. But that code doesn't exist since #4039 r22166.

Fixed on r23629

Thanks.