Fix wrong number of arguments in proxy.rb and writer.rb

[juicy-g]

• [ ] I have added or updated the specs/tests.
• [ ] I have verified that the specs/tests pass on my computer.
• [ ] I have not attempted to bump, or alter versions.
• [ ] This is a documentation change.
• [ x] This is a source change.

Description

[xaviershay]

I needed this change, thanks.

[bravecrayon]

I was just about to create a pull request for my fix for this but then I found this and #668.