Refactor monkey-patching of `PrivateAddressCheck` (#24122)

app/lib/request.rb

@@ -273,7 +273,9 @@ class Request
 
       def check_private_address(address, host)
         addr = IPAddr.new(address.to_s)
-        return if private_address_exceptions.any? { |range| range.include?(addr) }
+
+        return if Rails.env.development? || private_address_exceptions.any? { |range| range.include?(addr) }
+
         raise Mastodon::PrivateNetworkAddressError, host if PrivateAddressCheck.private_address?(addr)
       end
 

config/environments/development.rb

@@ -77,9 +77,3 @@ Rails.application.configure do
 end
 
 Redis.raise_deprecations = true
-
-module PrivateAddressCheck
-  def self.private_address?(*)
-    false
-  end
-end