set journal mode to wal when creating db. Trying to work around sqlite3.OperationalError: disk I/O error errors in CI that I can't reproduce locally. Also this allows reads to happen while writes are occurring. This should permit using the web interface for browsing while a large write load (e.g. bulk data loading from another tracker) is happening. Right now autogenerating issues locks up the tracker for reading with an error that the database is locked.

# In Python 3 the "anydbm" module was renamed to be "dbm" which is now a
# package containing the various implementations. The "wichdb" module's
# whichdb() function was moved to the new "dbm" module.

try:
    # old school first because <3 had a "dbm" module too...
    import anydbm
    from whichdb import whichdb
except ImportError:
    # python 3+
    import dbm as anydbm
    whichdb = anydbm.whichdb