patch 8.0.0971: 'winptydll' missing from :options

Problem:    'winptydll' missing from :options.
Solution:   Add the entry.
diff --git a/src/version.c b/src/version.c
index d820595..9f9b8ab 100644
--- a/src/version.c
+++ b/src/version.c
@@ -770,6 +770,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    971,
+/**/
     970,
 /**/
     969,