viewer: Fix missing save dialog label
viewer: Fix missing save dialog label

After a copy-and-paste mistake, the "Save Image" dialog was still called
"Save FMR".

Signed-off-by: Pawel Moll <54329ff2dc18fbe9d024c289c55c3d14a8ff27ff@pawelmoll.com>

pawelmoll/scannerAPI,pawelmoll/scannerAPI,pawelmoll/scannerAPI