#118 DB house-keeping not performed if DB_VERSION is updated

[Darkvater]

If DB_VERSION is updated the current minidlna version does not perform a database upgrade. Up until commit https://sourceforge.net/p/minidlna/git/ci/2521b3f23802a6b9341d28640c70ace44d3b2ac5/ a(n incremental) database was performed on a new version but looks like the approach was changed and now simply the DB is re-created. However the number 9 is hard-coded...
Remove that and the obsolete pragma update sql statement that is a no-op (or silent DB version upgrade without any changes). In keeping in-line, just re-create the DB if the current version is bigger than the local one.

diff:
https://github.com/Darkvater/minidlna/commit/01bec70ce967c447d0ce1e3f33d3029b67217f58

[Darkvater]

hmm, the commit is wrong, it should be:

    if (db_vers == DB_VERSION)
        return 0;
    if (db_vers > DB_VERSION)
        return -2;
    if (db_vers < 1)
        return -1;

    return db_vers;