When Nginx cannot connect to the helper agent socket, display the right socket filename in the error message.
When Nginx cannot connect to the helper agent socket, display the right socket filename in the error message.

phusion/passenger,antek-drzewiecki/passenger,bf4/passenger,phusion/passenger,phusion/passenger,bf4/passenger,kewaunited/passenger,antek-drzewiecki/passenger,cgvarela/passenger,bf4/passenger,kewaunited/passenger,kewaunited/passenger,cgvarela/passenger,kewaunited/passenger,clemensg/passenger,antek-drzewiecki/passenger,clemensg/passenger,antek-drzewiecki/passenger,cgvarela/passenger,jawj/passenger,cgvarela/passenger,clemensg/passenger,clemensg/passenger,bf4/passenger,phusion/passenger,antek-drzewiecki/passenger,jawj/passenger,clemensg/passenger,kewaunited/passenger,jawj/passenger,clemensg/passenger,bf4/passenger,phusion/passenger,bf4/passenger,clemensg/passenger,phusion/passenger,cgvarela/passenger,jawj/passenger,phusion/passenger,phusion/passenger,jawj/passenger,cgvarela/passenger,kewaunited/passenger,clemensg/passenger,cgvarela/passenger,antek-drzewiecki/passenger,jawj/passenger,antek-drzewiecki/passenger,jawj/passenger,cgvarela/passenger,antek-drzewiecki/passenger,kewaunited/passenger,kewaunited/passenger,bf4/passenger