Update fitssummary example to silently ignore invalid fits files
Update fitssummary example to silently ignore invalid fits files

mindriot101/rust-fitsio,mindriot101/rust-fitsio,mindriot101/rust-fitsio,mindriot101/rust-fitsio,mindriot101/rust-cfitsio,mindriot101/rust-fitsio,mindriot101/rust-cfitsio