Fix for bug 493135 . bltest crashes if it can't open the input file. r=nelson
Fix for bug 493135 . bltest crashes if it can't open the input file. r=nelson

nmav/nss,ekr/nss-old,nmav/nss,ekr/nss-old,nmav/nss,ekr/nss-old,nmav/nss,ekr/nss-old,ekr/nss-old,nmav/nss,nmav/nss,ekr/nss-old,nmav/nss,ekr/nss-old