2.2.1: Maintenance Release

Editor

• Handle mixed-cased filter terms in keyboard shortcut dialog (#3444) @knolleary
• Prevent duplicate links being added between nodes (#3442) @knolleary
• Fix to hide tooltip after removing subflow tab (#3391) @HiroyasuNishiyama
• Fix node validation to be applied to config node (#3397) @HiroyasuNishiyama
• Fix: Dont add wires to undo buffer twice (#3437) @Steve-Mcl

Runtime

• Improve module location parsing (of stack info) when adding hook (#3447) @Steve-Mcl
• Fix substitution of NR_NODE_PATH (#3445) @HiroyasuNishiyama
• Remove console.log when ignoring disabled module (#3439) @knolleary
• Improve "Unexpected Node Error" logging (#3446) @Steve-Mcl

Nodes

• Debug: Fix no-prototype-builtins bug in debug node and utils (#3394) @Alkarex
• Delay: Fix Japanese message of delay node (#3434)
• Allow nbRateUnits to be undefined when validating (#3443) @knolleary
• Coding help for recently added node-red Predefined Environment Variables (#3440) @Steve-Mcl