patch 8.1.2031: cursor position wrong when resizing and using conceal

Problem:    Cursor position wrong when resizing and using conceal.
Solution:   Set the flags that the cursor position is valid when setting the
            row and column during redrawing. (closes #4931)
diff --git a/src/version.c b/src/version.c
index c7f8764..61e41bd 100644
--- a/src/version.c
+++ b/src/version.c
@@ -758,6 +758,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2031,
+/**/
     2030,
 /**/
     2029,