This fixes #3399 by making sure that, when looking for a service, we check that it supports exactly the media we want.
This fixes #3399 by making sure that, when looking for a service, we check that it supports exactly the media we want.


jof/shotwell,jof/shotwell,abrauchli/shotwell,polymeris/shotwell,jimbonator/shotwell,polymeris/shotwell,damianmoore/shotwell,polymeris/shotwell,abrauchli/shotwell,ritchiewilson/shotwell,ritchiewilson/shotwell,h4ck3rm1k3/shotwell,jimbonator/shotwell,ritchiewilson/shotwell,Sanva/shotwell-gsoc,jof/shotwell,Sanva/shotwell-gsoc,Sanva/shotwell-gsoc,h4ck3rm1k3/shotwell,damianmoore/shotwell,damianmoore/shotwell,abrauchli/shotwell,jimbonator/shotwell,h4ck3rm1k3/shotwell