patch 9.0.0661: multi-byte "lastline" in 'fillchars' does not work properly

Problem:    Multi-byte "lastline" item in 'fillchars' does not work properly
            when the window is two columns wide.
Solution:   Compute the text length correctly. (closes #11280)

src/version.c

@@ -699,6 +699,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    661,
 /**/
     660,
 /**/