updated for version 7.3.501
Problem:    Error for "flush" not being defined when using Ruby command.
Solution:   Defined "flush" as a no-op method. (Kent Sibilev)
diff --git a/src/version.c b/src/version.c
index 720e45a..94d429e 100644
--- a/src/version.c
+++ b/src/version.c
@@ -715,6 +715,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    501,
+/**/
     500,
 /**/
     499,