Set torch to use one thread. Fixes a bug on docker

bob/pad/face/deep_pix_bis.py

@@ -13,6 +13,8 @@ from bob.io.image import to_matplotlib
 
 logger = logging.getLogger(__name__)
 
+# Fix for torch on docker (fixes CI linux runners):
+torch.set_num_threads(1)
 
 DEEP_PIX_BIS_PRETRAINED_MODELS = {
     "oulu-npu-p1": [