Photon: do not apply Photon on BuddyPress avatar change pages

We would need to disable Photon on BuddyPress Pages that allow you to change your avatar; Photon does indeed break the avatar cropping process. 

![photon-running](https://f.cloud.github.com/assets/426388/1861326/ae5dfd60-77c0-11e3-8e3c-93c80f6e7cee.jpg)

See [this thread](http://wordpress.org/support/topic/jetpack-tiled-mosaic-gallery-not-loading-all-images-1) for more details.