std: fix bug in http.headers where .put captures user-held variable
std: fix bug in http.headers where .put captures user-held variable

zig-lang/zig,raulgrell/zig,raulgrell/zig,zig-lang/zig,raulgrell/zig,andrewrk/zig,raulgrell/zig,andrewrk/zig,zig-lang/zig,raulgrell/zig