main: Teardown Messaging only after deleting environment.

In the destructor of Environment messages are written.
Hence Messaging.teardown() must not be called before the
destructor.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
conf: Avoid warning concerning unitialized variable c

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>