Update storage.php

Change line 141 from private to protected same as parent.
Now works fine in OC7
[tx-robot] updated from transifex
[tx-robot] updated from transifex
[tx-robot] updated from transifex
[tx-robot] updated from transifex
[tx-robot] updated from transifex
[tx-robot] updated from transifex
[tx-robot] updated from transifex
[tx-robot] updated from transifex
[tx-robot] updated from transifex
[tx-robot] updated from transifex
[tx-robot] updated from transifex
[tx-robot] updated from transifex
[tx-robot] updated from transifex
[tx-robot] updated from transifex
[tx-robot] updated from transifex
Imprint: Bring copyright notice up to date.
Imprint: Change app version number to 0.2.0.
Imprint: Remove all backwards compatibility logic.
Imprint: Rename files for transparency reasons.