patch 8.0.0689: ~ character not escaped when extending search pattern

Problem:    The ~ character is not escaped when adding to the search pattern
            with CTRL-L. (Ramel Eshed)
Solution:   Escape the character. (Christian Brabandt)
diff --git a/src/version.c b/src/version.c
index 7bf3f4e..64f035d 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    689,
+/**/
     688,
 /**/
     687,