Convert throw in IPAddress to throw_exception
Convert throw in IPAddress to throw_exception

Summary: Unbreak -fno-exceptions support for this file.

Reviewed By: yfeldblum

Differential Revision: D21043400

fbshipit-source-id: aceea45c32d143c723ad6bae68a7403f14d7e0f2

facebook/folly,facebook/folly,facebook/folly,facebook/folly,facebook/folly