patch 9.0.0309: invalid memory access when cmdheight is zero

Problem:    Invalid memory access when cmdheight is zero.
Solution:   Check index in w_lines is smaller than Rows.
diff --git a/src/version.c b/src/version.c
index eb05f9a..c69e46c 100644
--- a/src/version.c
+++ b/src/version.c
@@ -708,6 +708,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    309,
+/**/
     308,
 /**/
     307,