patch 8.2.2644: prop_clear() causes a screen update even when nothing changed

Problem:    prop_clear() causes a screen update even when nothing changed.
Solution:   Only redraw when a property was cleared. (Dominique Pellé)
diff --git a/src/version.c b/src/version.c
index 3d69e9c..6fda8fc 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2644,
+/**/
     2643,
 /**/
     2642,