patch 8.2.4644: redrawing too often when 'relativenumber' is set

Problem:    Redrawing too often when 'relativenumber' is set.
Solution:   Only redraw when the cursor line changed. (Lewis Russell,
            closes #10040)

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    4644,
 /**/
     4643,
 /**/