Fix upgrading storage database from previous versions of LiteDB

[matus-tomlein]

In the 0.6.1 release of the tracker, the LiteDB dependency was upgraded from v4 to v5.

In cases where the storage database was previously saved using the v4 version of the LiteDB dependency, this raised an exception when the database was loaded using the v5 LiteDB:

LiteException: File is not a valid LiteDB database format or contains a invalid password.

To fix this issue, we need to enable the Upgrade attribute when creating the connection in LiteDB.