patch 9.0.0652: 'smoothscroll' not tested with 'number' and "n" in 'cpo'

Problem:    'smoothscroll' not tested with 'number' and "n" in 'cpo'.
Solution:   Add tests, fix uncovered problem.
diff --git a/src/version.c b/src/version.c
index c84d309..abc67c0 100644
--- a/src/version.c
+++ b/src/version.c
@@ -700,6 +700,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    652,
+/**/
     651,
 /**/
     650,