QuickRender gets into an infinite loop

[VilleOlof]

Describe the bug
When it tries to find if a file already exists to get a new file name with a _num suffix, it gets into a infinite loop when the name doesnt have a _num suffix, so it succeds with "video_1.mp4" but fails with "video.mp4" in the same directory.

To Reproduce
Steps to reproduce the behavior:

1. Make a video file with the name "video.mp4"
2. Add that path and filename to a quickrender profile
3. Reload the profile

Expected behavior
It shouldnt uhhh be stuck in an infinite loop

Desktop (please complete the following information):

• OS: Windows
• Version 1.0.6