v3.0.3

This update fixes a security vulnerability (again discovered and reported to us by security researcher pearl) and several bugs.

The update is mandatory for all GUI wallets.

• Restored full backup which previously didn't include rocksdb folder. If you have a backup created on desktop versions 3.0.0 to 3.0.2, that backup is broken, please create a new one after upgrading.
• Fixed a bug that prevented accepting of some contracts, in particular Freebe contracts didn't work.
• Fixed a bug that prevented replacement of more than one Order Provider at a time when prompted by a suggestion from a hub.
• Linux wallet is now distributed as AppImage, which allows it to run on greater number of Linux distributions. Previously, the wallet didn't start on some Linux distributions. Linux wallet also uses a newer version of NWJS now. Please backup (by making a copy of your ~/.config/byteball folder while the wallet is not running) before upgrading, just in case.

SHA256 hash of the linux AppImage is ee8ddba9bec2b0355237304140431a253fdc6b6999c30ff8809db2167f96ec7a, binaries for other platforms are already signed in ways that are standard on the respective platforms.