Only undef the id method on ACL and Owner if it is currently defined …

…to play better with third party libraries

lib/aws/s3/acl.rb

@@ -385,7 +385,7 @@ def build
       class Grantee
         include SelectiveAttributeProxy #:nodoc:
 
-        undef_method :id # Get rid of Object#id
+        undef_method :id if method_defined?(:id) # Get rid of Object#id
 
         def initialize(attributes = {})
           # Set default values for attributes that may not be passed in but we still want the object

lib/aws/s3/owner.rb

@@ -7,7 +7,7 @@ module S3
     #
     # You can retrieve the owner of the current account by calling Owner.current.
     class Owner
-      undef_method :id # Get rid of Object#id
+      undef_method :id if method_defined?(:id) # Get rid of Object#id
       include SelectiveAttributeProxy
 
       class << self