Fix broken link to Google Shell Style Guide

diff --git a/doc/safe-shell.mdwn b/doc/safe-shell.mdwn
index 7b24040f27a906a60df551fbf105c2c4fb4f289f..d6e5049b116e690fd78562b75b540a45784fd22a 100644 (file)
--- a/doc/safe-shell.mdwn
+++ b/doc/safe-shell.mdwn
@@ -114,7 +114,7 @@ TODO: mumble `mktemp`?
 
 ## Other resources
 
-Google has a [Shell Style Guide](http://google-styleguide.googlecode.com/svn/trunk/shell.xml). As the name suggests, it primarily focuses on good style, but some items are safety/security-relevant.
+Google has a [Shell Style Guide](https://google.github.io/styleguide/shell.xml). As the name suggests, it primarily focuses on good style, but some items are safety/security-relevant.
 
 ## Conclusion