Automatic merge from submit-queue

remove svg mime type extension
Signed-off-by: sakeven <jc5930@sina.cn>



**What this PR does / why we need it**:

I found that [kubernetes requires go version 1.6 or greater](https://github.com/kubernetes/kubernetes/blob/master/hack/lib/golang.sh#L335).
While the [commit](https://github.com/golang/go/commit/21e47d831bafb59f22b1ea8098f709677ec8ce33)  which adds "image/svg+xml" type for extension ".svg", has been merged to go from version 1.5 to 1.9beta.

So it's safe to remove code ```mime.AddExtensionType(".svg", "image/svg+xml")```.

**Special notes for your reviewer**:

**Release note**:

```
NONE
```