updated kseq.h to bring in empty line bug fix from klib/37b020f9db

This solves the issue with bioawk that I opened yesterday:

    $ echo ">a\\nATAGA\\n\\n>b\\nAGATTAG\\n>c\\nAGATAG" | ./awk -cfastx '{print $name}'
    a
    b
    c

Note that I removed `-ansi` from the `Makefile` so `kseq.h` would compile.