**Do you want to request a *feature* or report a *bug*?**
Bug

**What is the current behavior?**
I've started recieving this warning about my SVGs which is using [feGaussianBlur](https://developer.mozilla.org/en-US/docs/Web/SVG/Element/feGaussianBlur): 
`Warning: Expected server HTML to contain a matching <feGaussianBlur> in <filter>.`

**What is the expected behavior?**
Should be no warnings because there are no difference.

**Which versions of React, and which browser / OS are affected by this issue? Did this work in previous versions of React?**
Such behavior started right after updating to `React 16.0.0-rc.3` and never happened with `React 15.6.1`
instance: Instance,
    type: string,
    props: Props,
    rootContainerInstance: Container,
    hostContext: HostContext,
    internalInstanceHandle: Object,
  ): null | Array<mixed> {
    precacheFiberNode(internalInstanceHandle, instance);
    
    
    updateFiberProps(instance, props);
    let parentNamespace: string;
    if (__DEV__) {
      const hostContextDev = ((hostContext: any): HostContextDev);
      parentNamespace = hostContextDev.namespace;
    } else {
      parentNamespace = ((hostContext: any): HostContextProd);
    }
    return diffHydratedProperties(
      instance,
      type,
      props,
      parentNamespace,
      rootContainerInstance,
    );
  },
  hydrateTextInstance(
    textInstance: TextInstance,
    text: string,
    internalInstanceHandle: Object,