patch 9.0.0590: after exiting Insert mode spelling not checked in next line

Problem:    After exiting Insert mode spelling is not checked in the next
            line.
Solution:   When spelling is enabled redraw the next line after exiting Insert
            mode in case the spell highlight needs updating.

src/version.c

@@ -699,6 +699,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    590,
 /**/
     589,
 /**/