patch 8.2.2489: current buffer is wrong after deletebufline() fails

Problem:    current buffer is wrong after deletebufline() fails to delete a
            line in another buffer.
Solution:   Restore the current buffer.
diff --git a/src/version.c b/src/version.c
index 8b5de13..18f0b84 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2489,
+/**/
     2488,
 /**/
     2487,