Revert "Add example label to active_support/configurable"

This reverts commit 693f770a.

Reason: to be able to revert f480b2ce

activesupport/lib/active_support/configurable.rb

@@ -32,6 +32,7 @@ def #{name}=(value); config.#{name} = value; end
     end
 
     # Reads and writes attributes from a configuration <tt>OrderedHash</tt>.
+    # 
     # Example:
     # 
     #   require 'active_support/configurable'