patch 8.1.2121: mode is not updated when switching to terminal

Problem:    Mode is not updated when switching to terminal in Insert mode.
Solution:   Redraw the mode when entering a terminal window. (Jason Franklin)
diff --git a/src/version.c b/src/version.c
index f668b97..f4d0275 100644
--- a/src/version.c
+++ b/src/version.c
@@ -754,6 +754,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2121,
+/**/
     2120,
 /**/
     2119,