Fix the link to the mailing list

README.md

@@ -133,7 +133,7 @@ of the guarantee that mat2 won't modify the data of their files, there is the
 # Contact
 
 If possible, use the [issues system](https://0xacab.org/jvoisin/mat2/issues)
-or the [mailing list](https://mailman.boum.org/listinfo/mat-dev)
+or the [mailing list](https://www.autistici.org/mailman/listinfo/mat-dev)
 Should a more private contact be needed (eg. for reporting security issues),
 you can email Julien (jvoisin) Voisin at `julien.voisin+mat2@dustri.org`,
 using the gpg key `9FCDEE9E1A381F311EA62A7404D041E8171901CC`.