Add an edge_about_to_close() call to ap_about_to_close().

Fixes #17876

changes/bug17876

@@ -0,0 +1,5 @@
+  o Minor bugfixes:
+    - When closing an entry connection, generate a warning if we should
+      have sent an end cell for it but we haven't.  Fixes bug 17876;
+      bugfix on 0.2.3.2-alpha.
+

src/or/connection_edge.c

@@ -538,6 +538,8 @@ connection_ap_about_to_close(entry_connection_t *entry_conn)
   edge_connection_t *edge_conn = ENTRY_TO_EDGE_CONN(entry_conn);
   connection_t *conn = ENTRY_TO_CONN(entry_conn);
 
+  connection_edge_about_to_close(edge_conn);
+
   if (entry_conn->socks_request->has_finished == 0) {
     /* since conn gets removed right after this function finishes,
      * there's no point trying to send back a reply at this point. */