Version check (torchvision) >= 0.10 error fix

[EherSenaw]

TL;DR ) Fixed util/misc.py's version checking method for torchvision to be compatible with torchvision >= 0.10.0

Since I was interested in your paper, Sparse DETR, I was trying to run(train/test) model within Google Colab environment.

During the initial run, I found out that torchvision version checking method does not work as intended:

• My torchvision version was0.10.1, but the checking method treated as 0.1.

Solved by replacing

float(torchvision.__version__[:3]) < 0.5

with

float(torchvision.__version__.split('.')[1]) < 5

And for <0.7, similarly fixed.

Therefore, I request pull-request to fix this issue.

Thank you.
Taewoo Jeong.