maps: handle sqlite lock error triggered by PRAGMA statements "self._db.execute('PRAGMA cache_size=%d' % (-cachesize))" could raise "OperationalError: database is locked". Therefore move PRAGMA statements inside "self._transaction" which handles the "locked" error automatically.

#!/bin/sh
. $(dirname $0)/common.sh

for b in `hg branches -aq` ; do
    hg co $b || break
    echo verifying $b
    hg svn verify
done