Custom Style - Border Width Top - on a basic button doesn't decrease until scene is reloaded.

**Godot version:**

3.2.2

**OS/device including version:**

Windows 10 - 2004

**Issue description:**

Basically, if you increase the border top or bottom it will increase the visible size of the button. Reducing the borders size

**Steps to reproduce:**
Add Control, Add button, edit style, increase top / bottom, decrease top / bottom, to fix change scenes.

Demo:
https://dl.dropboxusercontent.com/s/b7zwabe1cs7inrv/Si4yut5nOt.mp4

Very low prio, just figured it was worth reporting.