patch 8.0.1796: GUI: click on tab fails when the focus is in a terminal

Problem:    GUI: click on tab fails when the focus is in a terminal window.
Solution:   Handle K_TABLINE.
diff --git a/src/version.c b/src/version.c
index 7a28f46..7fbca85 100644
--- a/src/version.c
+++ b/src/version.c
@@ -762,6 +762,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1796,
+/**/
     1795,
 /**/
     1794,