fix typo in the comments
diff --git a/system/core/CodeIgniter.php b/system/core/CodeIgniter.php
index 88e730b..b1da42d 100644
--- a/system/core/CodeIgniter.php
+++ b/system/core/CodeIgniter.php
@@ -145,7 +145,7 @@
  * The subclass prefix allows CI to know if a core class is
  * being extended via a library in the local application
  * "libraries" folder. Since CI allows config items to be
- * overriden via data set in the main index.php file,
+ * overridden via data set in the main index.php file,
  * before proceeding we need to know if a subclass_prefix
  * override exists. If so, we will set this value now,
  * before any classes are loaded