Fix typo in comments
diff --git a/system/core/Common.php b/system/core/Common.php
index ce324a1..ad3ca9f 100644
--- a/system/core/Common.php
+++ b/system/core/Common.php
@@ -677,7 +677,7 @@
* of CodeIgniter.php. The main reason we use this is to simulate
* a complete custom exception handler.
*
- * E_STRICT is purposivly neglected because such events may have
+ * E_STRICT is purposively neglected because such events may have
* been caught. Duplication or none? None is preferred for now.
*
* @link http://insomanic.me.uk/post/229851073/php-trick-catching-fatal-errors-e-error-with-a