Minor fix in python viewer.

[0mdc]

Motivation and Context

This fixes an indentation errors in the python viewer that causes the batch renderer to execute multiple times. This is not an issue under normal usage.

How Has This Been Tested

Tested locally.

Types of changes

• [ ] Docs change / refactoring / dependency upgrade
• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)