updated for version 7.4.528
Problem:    Crash when using matchadd() (Yasuhiro Matsumoto)
Solution:   Copy the match regprog.
diff --git a/src/version.c b/src/version.c
index a3adca8..c674ce1 100644
--- a/src/version.c
+++ b/src/version.c
@@ -742,6 +742,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    528,
+/**/
     527,
 /**/
     526,