conn_is_closed should return 1 if get_last_sys_error is WSAECONNRESET

CLA: trivial

Reviewed-by: Paul Dale <paul.dale@oracle.com>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/8590)

(cherry picked from commit 0b885f72c2)

ssl/statem/statem_srvr.c

@@ -774,6 +774,10 @@ static ossl_inline int conn_is_closed(void)
 #if defined(ECONNRESET)
     case ECONNRESET:
         return 1;
+#endif
+#if defined(WSAECONNRESET)
+    case WSAECONNRESET:
+        return 1;
 #endif
     default:
         return 0;