updated for version 7.4.639

Problem:    Combination of linebreak and conceal doesn't work well.
Solution:   Fix the display problems. (Christian Brabandt)

src/version.c

@@ -741,6 +741,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    639,
 /**/
     638,
 /**/