Auto-upgrade to 6.40.0.0 (#423)

Co-authored-by: Auto-upgrade to 6.40.0.0 <s4nchez@users.noreply.github.com>

Author: daviddenton

gradle.properties

@@ -8,4 +8,4 @@ kotlin.code.style=official
 kotlin.incremental=true
 
 # Version properties
-http4kVersion=6.39.1.0
+http4kVersion=6.40.0.0