patch 8.1.1643: sign placement is wrong when 'foldcolumn' is set

Problem:    Sign placement is wrong when 'foldcolumn' is set.
Solution:   Adjust the column computation. (Yee Cheng Chin, closes #4627)
diff --git a/src/version.c b/src/version.c
index f71c75c..c7e2a16 100644
--- a/src/version.c
+++ b/src/version.c
@@ -778,6 +778,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1643,
+/**/
     1642,
 /**/
     1641,