**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`
warnForDeletedHydratableElement(parentContainer, (instance: any));
      } else {
        warnForDeletedHydratableText(parentContainer, (instance: any));
      }
    }
  },
  didNotHydrateInstance(
    parentType: string,
    parentProps: Props,
    parentInstance: Instance,
    instance: Instance | TextInstance,
  ) {
    if (__DEV__ && parentProps[SUPPRESS_HYDRATION_WARNING] !== true) {
      if (instance.nodeType === 1) {
        warnForDeletedHydratableElement(parentInstance, (instance: any));
      } else {
        warnForDeletedHydratableText(parentInstance, (instance: any));
      }
    }
  },
  didNotFindHydratableContainerInstance(
    parentContainer: Container,
    type: string,
    props: Props,
  ) {
    if (__DEV__) {
      warnForInsertedHydratedElement(parentContainer, type, props);
    }
  },
  didNotFindHydratableContainerTextInstance(