fixes #1312 Adjust Date and Time displays 1969 when no EXIF data
fixes #1312 Adjust Date and Time displays 1969 when no EXIF data

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