patch 8.0.0686: extra redraw when using CTRL-L in second window

Problem:    When typing CTRL-L in a window that's not the first one, another
            redraw will happen later. (Christian Brabandt)
Solution:   Reset must_redraw after calling screenclear().

src/version.c

@@ -764,6 +764,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    686,
 /**/
     685,
 /**/