Fix: HTTP signature wasn't being sent in AP POSTs

src/Web/ActivityPub.hs

@@ -321,6 +321,6 @@ httpPostAP manager uri headers sign value =
                     let (k, s) = sign b
                     in  (Nothing, k, s)
             req'' <- signRequest headers sign' Nothing req'
-            httpNoBody req' manager
+            httpNoBody req'' manager
     where
     consHeader n b r = r { requestHeaders = (n, b) : requestHeaders r }