patch 8.2.1967: the session file does not restore the alternate file

Problem:    The session file does not restore the alternate file.
Solution:   Add ":balt".  Works like ":badd" and also sets the buffer as the
            alternate file.  Use it in the session file. (closes #7269,
            closes #6714)
diff --git a/src/version.c b/src/version.c
index 1fbae19..fe89862 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1967,
+/**/
     1966,
 /**/
     1965,