Improve file-extension matching in serveFileFromZIP.
Improve file-extension matching in serveFileFromZIP.

More efficient, and fixes matching of the dot character.

IljaZakharov/benchexec,ultimate-pa/benchexec,sosy-lab/benchexec,ultimate-pa/benchexec,martin-neuhaeusser/benchexec,martin-neuhaeusser/benchexec,sosy-lab/benchexec,martin-neuhaeusser/benchexec,dbeyer/benchexec,dbeyer/benchexec,dbeyer/benchexec,dbeyer/benchexec,ultimate-pa/benchexec,ultimate-pa/benchexec,sosy-lab/benchexec,IljaZakharov/benchexec,sosy-lab/benchexec,IljaZakharov/benchexec,sosy-lab/benchexec,ultimate-pa/benchexec,IljaZakharov/benchexec,martin-neuhaeusser/benchexec,sosy-lab/benchexec,ultimate-pa/benchexec