Prime tower outside plate

[AkashCherukuri]

Describe the bug
The prime tower is made outside the build plate

To Reproduce
Steps to reproduce the behavior:

1. Mave multiple plates with prime towers
2. Click slice

Expected behavior
The prime tower should be inside the build volume

Screenshots

Desktop (please complete the following information):

• OS: Windows
• Version

Smartphone (please complete the following information):

• Device: [e.g. iPhone6]
• OS: [e.g. iOS8.1]
• Browser [e.g. stock browser, safari]
• Version [e.g. 22]

Additional context
Add any other context about the problem here.