Update Cargo.toml

Use new version of forum module.

Co-Authored-By: Mokhtar Naamani <mokhtar.naamani@gmail.com>

Cargo.toml

@@ -193,4 +193,4 @@ rev = '6dfc3e8b057bb00322136251a0f10305fbb1ad8f'
 default_features = false
 git = 'https://github.com/joystream/substrate-forum-module'
 package = 'substrate-forum-module'
-rev = '4615fdc126ad7f3fe0fef7620177b38c307d9e2d'
+rev = '5ab4944344966e0b460f3883cbc45eab94ef666e'