[ci skip] Fix a comment typo
diff --git a/index.php b/index.php
index 7f9a777..d02b6bb 100755
--- a/index.php
+++ b/index.php
@@ -91,7 +91,7 @@
 
 /*
  *---------------------------------------------------------------
- * SYSTEM DIRCTORY NAME
+ * SYSTEM DIRECTORY NAME
  *---------------------------------------------------------------
  *
  * This variable must contain the name of your "system" directory.