explicit library export of ConfigurationProxy symbol

Without this library it was impossible to acquire the framerate
model of any video camera on Windows platform (.dll)

[Guillaume: ci msg edited for details]

Change-Id: Ib06a680bc2a5c90210949a868dc7b0cb8adc64ba
Reviewed-by: Guillaume Roguez <guillaume.roguez@savoirfairelinux.com>