patch 8.0.0576: can't build when configure choses "install-sh"

Problem:    Can't build when configure choses "install-sh". (Daniel Hahler)
Solution:   Always use install-sh.  Fix remaining use of mkinstalldirs.
            (closes #1647)
diff --git a/src/version.c b/src/version.c
index 60dbdf4..b0ccc14 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    576,
+/**/
     575,
 /**/
     574,