Giving score 0: backend can't differ null score and 0 score

[nichoio]

After a score was given and the transaction is being processed, the value in scores[] in the contract is still 0. Since this is different from null being the default value in DB, null gets overriden with 0.
The proper score will never be saved bc db thinks the transaction is confirmed changing those values.

[nichoio]

Contract now requires scores > 0.
This will do as a workaround for now. Ofc not a great solution but otherwise a larger refactoring of contract and backend would be necessary.