Generated code needs gofix

[xakep666]

Generated code imports golang.org/x/net/context but since go 1.7 it became a part of standard library and gofix replaces import with context.

Before gofix:

import (
    "bytes"
    "compress/gzip"
    "io"
    "net/http"
    "os"
    "path"

    "golang.org/x/net/context"
    "golang.org/x/net/webdav"
)

After gofix:

import (
    "bytes"
    "compress/gzip"
    "io"
    "net/http"
    "os"
    "path"

    "context"
    "golang.org/x/net/webdav"
)