Fix puma_bind unix socket path

[hnatt]

I don't know what was the decision behind setting all paths with File.join instead of an interpolated string, and if it is worth rolling back (so I didn't), but File.join seems to mess up the unix socket URL:

> File.join('unix://', '/home/deploy/app', 'tmp', 'sockets', 'puma.socket') # => "unix:/home/deploy/app/tmp/sockets/puma.socket"
> File.join('unix://home/deploy/app', 'tmp', 'sockets', 'puma.socket') # => "unix://home/deploy/app/tmp/sockets/puma.socket"

[seuros]

Nice catch. Thanks you.

[hnatt]

No problem! Should all path assignments stay lambdas with File.join? I think it's nicer and simpler when they are just strings, like in "Configurable options" in README. I doubt somebody will ever deploy Puma to a Windows or OS/2 host, where path separators are different. If they do, it'll be their least problem.

[seuros]

No, we can change this. The is no reason to use join.

[hnatt]

But why was File.join used in the first place? Won't it break someones workflow if we throw away the lambdas?

[seuros]

No specific reason, probably habit.
shared_path is undefined without the lambda. It used to delay it resolution.

[hnatt]

You are right about lamdas.

Probably I'll leave it as is. It seems to work and I feel uneasy refactoring something not knowing if it breaks.