generate_blink_seq_randomly does not work for 21 frames

[SanderGi]

I ran into an issue with generate_blink_seq_randomly while testing short audio inputs.

For reference, src.generate_batch.py has the following implementation of generate_blink_seq_randomly:

def generate_blink_seq_randomly(num_frames):
    ratio = np.zeros((num_frames,1))
    if num_frames<=20:
        return ratio
    frame_id = 0
    while frame_id in range(num_frames):
        start = random.choice(range(min(10,num_frames), min(int(num_frames/2), 70))) 
        if frame_id+start+5<=num_frames - 1:
            ratio[frame_id+start:frame_id+start+5, 0] = [0.5, 0.9, 1.0, 0.9, 0.5]
            frame_id = frame_id+start+5
        else:
            break
    return ratio

When the number of frames is 21, int(num_frames/2) evaluates to 10 and min(10,num_frames) also evaluates to 10 meaning we get random.choice(10, 10) which is invalid and throws an error. A correct if condition would look like if int(num_frames / 2) < 11 instead of if num_frames<=20. Would submitting a PR that fixes this be appropriate?