[BUG] Duplicate App Crash

**Describe the bug**
Crashes Springboard when an identical app is added to the app's stack

**To Reproduce**
1. Add app X to the stack of app X
2. Boomshakahlakah

**Expected behavior**
"Hey you can't do that!" - a pop-up would be nice

**Screenshots**
None

**Smartphone (please complete the following information):**
Any device

**Additional context**
Nope