Fix swift link (#776)

Author: ArtskydJ

docs/rules/no-for-loop.md

@@ -2,7 +2,7 @@
 
 There's no reason to use old school for loops anymore for the common case. You can instead use for-of loop (with `.entries()` if you need to access the index).
 
-Off-by-one errors are one of the most common bugs in software. [Swift actually removed this completely from the language.](https://github.com/apple/swift-evolution/blob/master/proposals/0004-remove-pre-post-inc-decrement.md).
+Off-by-one errors are one of the most common bugs in software. [Swift actually removed this completely from the language.](https://github.com/apple/swift-evolution/blob/master/proposals/0007-remove-c-style-for-loops.md).
 
 This rule is fixable unless index or element variables were used outside of the loop.