Use ::new instead of #initialize for ghost methods [ci-skip]

RDoc translates `#initialize` to `::new` for real methods, but it does
not do so for ghost methods.

Author: jonathanhefner

activesupport/lib/active_support/message_encryptors.rb

@@ -28,8 +28,8 @@ class MessageEncryptors < Messages::RotationCoordinator
     # <tt>transitional = false</tt>.
 
     ##
-    # :method: initialize
-    # :call-seq: initialize(&secret_generator)
+    # :singleton-method: new
+    # :call-seq: new(&secret_generator)
     #
     # Initializes a new instance. +secret_generator+ must accept a salt and a
     # +secret_length+ kwarg, and return a suitable secret (string) or secrets

activesupport/lib/active_support/message_verifiers.rb

@@ -28,8 +28,8 @@ class MessageVerifiers < Messages::RotationCoordinator
     # <tt>transitional = false</tt>.
 
     ##
-    # :method: initialize
-    # :call-seq: initialize(&secret_generator)
+    # :singleton-method: new
+    # :call-seq: new(&secret_generator)
     #
     # Initializes a new instance. +secret_generator+ must accept a salt, and
     # return a suitable secret (string). +secret_generator+ may also accept