Bugfix: mark edited proof as obsolete if the answer of prover is unknown.

If the answer of prover was unknown and reason of the answer was not None
and the proof was edited, it was not marked as obsolete. This commit
fixes this problem.

Contributed by Stefan Berghofer.

src/session/session_scheduler.ml

@@ -862,7 +862,7 @@ let edit_proof ~cntexample eS sched ~default_editor a =
   else
     let callback a res =
       match res with
-      | Done {Call_provers.pr_answer = Call_provers.Unknown ("", None)} ->
+      | Done {Call_provers.pr_answer = Call_provers.Unknown ("", _)} ->
         set_proof_state ~notify ~obsolete:true ~archived:false
           JustEdited a
       | _ ->
@@ -874,7 +874,7 @@ let edit_proof ~cntexample eS sched ~default_editor a =
 let edit_proof_v3 ~cntexample eS sched ~default_editor ~callback a =
   let callback a res =
     match res with
-    | Done {Call_provers.pr_answer = Call_provers.Unknown ("", None)} ->
+    | Done {Call_provers.pr_answer = Call_provers.Unknown ("", _)} ->
       callback a
     | _ -> ()
   in