Repro steps:
1. Open Scene1 from the attached project
2. Preview the particle system by selecting it in the hierarchy.
3. Observe how red sub emitter particles are still being spawned, even when their parent particles have stopped moving.

Expected outcome:
The over-distance emission sub emitters to not spawn when their parent particles are not moving.

Notes:
- I've added a bit of gravity to visualize this easier; gravity on the sub emitter can be set to 0 and its sorting fudge to -10 to see them stationary
- Not a regression, happens in 2017.1.0p5 as well