http_driver: set sequenceNumber

src/syndicate/drivers/http_driver.nim

@@ -117,6 +117,7 @@ type
     ds: Cap
     bindings: Bag[Value]
       # cannot make a bag of HttpBinding, no `==` operator
+    sequenceNumber: BiggestInt
   Session = ref object
     facet: Facet
     driver: Driver
@@ -250,6 +251,8 @@ proc service(ses: Session) =
     ses.facet.run do (turn: var Turn):
       var (n, req) = parseRequest(ses.conn, cast[string](data))
       if n > 0:
+        inc(ses.driver.sequenceNumber)
+        req.sequenceNumber = ses.driver.sequenceNumber
         req.port = BiggestInt ses.port
         inFacet(turn) do (turn: var Turn):
           preventInertCheck(turn)