Previously, the first frame was displayed from frame 0, but now, the first frame is only displayed when the current frame is equal or greater than the keyframe number. The previous system was logical when the grease pencil was not an object, but now it seems more logical to display the keyframe if the current frame is equal to or greater than the keyframe number. Reviewed By: mendio, pepeland Differential Revision: https://developer.blender.org/D7851