Steps to reproduce:
1. Download 94699_repro.zip and open "Particles" scene
2. Select "Parent" game object
3. Navigate to Particle system's Sub Emitters module
4. Open Selection window (to open it press circle near the Particle system input field)
5. Add "Hit" particle system as sub emitter
6. Press Enter
7. Chose "No, Remove" option or close the pop-up window

Expected results: Sub emitter particles are cleared from the scene window
Actual results: Sub emitter particles are rendered in the scene window

workaround: Select "Hit" particle system and simulate it

Reproduced with: 2017.3.0a7, 2017.2.0b10, 2017.1.f1, 5.6.3p2, 5.5.4p4, 5.5.0b1