patch 8.2.1772: cannot use CTRL-W <Down> to move out of a terminal window

Problem:    Cannot use CTRL-W <Down> to move out of a terminal window.
Solution:   Use special_to_buf() instead of mb_char2bytes(). (closes #7045)
diff --git a/src/version.c b/src/version.c
index d390212..d5c8f30 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1772,
+/**/
     1771,
 /**/
     1770,