Remove dead code written for PHP 5.2
diff --git a/system/libraries/Email.php b/system/libraries/Email.php
index be89d65..5049578 100644
--- a/system/libraries/Email.php
+++ b/system/libraries/Email.php
@@ -1514,14 +1514,7 @@
 		// which only works with "\n".
 		if ($this->crlf === "\r\n")
 		{
-			if (is_php('5.3'))
-			{
-				return quoted_printable_encode($str);
-			}
-			elseif (function_exists('imap_8bit'))
-			{
-				return imap_8bit($str);
-			}
+			return quoted_printable_encode($str);
 		}
 
 		// Reduce multiple spaces & remove nulls