community/qbittorrent: upgrade to 4.6.6

v4.6.6 changelog:

• BUGFIX: Fix handling of tags containing '&' character (glassez)
• BUGFIX: Show scroll bar in Torrent Tags dialog (glassez)
• BUGFIX: Apply bulk changes to correct content widget items (glassez)
• BUGFIX: Hide zero status filters when torrents are removed (glassez)
• BUGFIX: Fix Incomplete Save Path cannot be changed for torrents without metadata (glassez)
• WEBUI: Correctly apply changed "save path" of RSS rules (glassez)
• WEBUI: Clear tracker list on full update (skomerko)
• OTHER: Update User-Agent string for internal downloader and search engines (cayenne17)
• Full changes