patch 9.0.1551: position of marker for 'smoothscroll' not computed correctly

Problem:    Position of marker for 'smoothscroll' not computed correctly.
Solution:   Take 'list' and other options into account. (Luuk van Baal,
            closes #12393)
diff --git a/src/version.c b/src/version.c
index 923ea97..cc7c4e1 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1551,
+/**/
     1550,
 /**/
     1549,