patch 8.1.0966: one terminal test is flaky

Problem:    One terminal test is flaky.
Solution:   Add to list of flaky tests.
diff --git a/src/version.c b/src/version.c
index 328d658..a732545 100644
--- a/src/version.c
+++ b/src/version.c
@@ -780,6 +780,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    966,
+/**/
     965,
 /**/
     964,