net/http: extra space in panic message

[kanata2]

In net/http/server.go,

if pattern == "" {
    panic("http: invalid pattern " + pattern)
}

I think the last space of "http: invalid pattern " and + pattern are unnecessary because pattern is an empty string, so please review this 🙏
I'll send a change request if there is no problem.

[bradfitz]

Yeah, that looks like a copy/paste oversight from a few lines later.

Sure, send a change.

[gopherbot]

CL https://golang.org/cl/50350 mentions this issue.