Incorrect keypoint array indexing in video_processing.py

### Description
There is an issue in the `crop_frames_and_get_transforms` function in `util/inference/video_processing.py`. The keypoint array indexing is incorrect, which causes the keypoints to be appended to the wrong list. When target face count is set to be >1 (multiple faces), result video would be wrong.

### Current Code
```
for q in range (len(target_embeds)):
kps_array[0].append([])
```

### Suggested Fix
The indexing should be corrected to append the keypoints to the correct list:
```
for q in range (len(target_embeds)):
kps_array[q].append([])
```