V7.4.4

This is the fourth bugfix release of Tribler 7.4.x series.
It fixes Tribler crashing randomly with lambda message. Also, it includes a backport of 7.5 fixes for TorrentChecker SQL queries, which improves performance for people with big Channels databases.

Changelog:

• Hacky fix for config upgrading
• Backport TorrentChecker fixes from devel
• Removed set_filepieceranges
• Catch ValueErrors in connect_to_tracker (to deal with invalid urls)
• Fix for checkpoint timeouts
• Fix dir writability check