patch 8.0.1711: term_setsize() is not implemented yet

Problem:    Term_setsize() is not implemented yet.
Solution:   Implement it.
diff --git a/src/version.c b/src/version.c
index b340f11..255e24b 100644
--- a/src/version.c
+++ b/src/version.c
@@ -763,6 +763,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1711,
+/**/
     1710,
 /**/
     1709,