Allows compilation with both valac 0.18.x and 0.19.x. Closes #6406.
Allows compilation with both valac 0.18.x and 0.19.x. Closes #6406.

damianmoore/shotwell,damianmoore/shotwell,ritchiewilson/shotwell,jimbonator/shotwell,abrauchli/shotwell,ritchiewilson/shotwell,damianmoore/shotwell,polymeris/shotwell,ritchiewilson/shotwell,abrauchli/shotwell,polymeris/shotwell,abrauchli/shotwell,jimbonator/shotwell,jimbonator/shotwell,polymeris/shotwell