Don't notify URI changes for internal buffers.
Don't notify URI changes for internal buffers.

notify::uri happens _before_ the request-resource-hook is run.

The latter defers the loading of external resources to a new web buffer for
internal buffers.  It this scenario, the load for the internal buffer is
canceled.  Then the notify::uri is useless for this buffer.

jmercouris/NeXT,jmercouris/NeXT