Enable tensorflow v2 tensor shape

Signed-off-by: Jim Martens <github@2martens.de>

src/twomartens/masterthesis/main.py

@@ -173,6 +173,7 @@ def _ssd_val(args: argparse.Namespace) -> None:
     from twomartens.masterthesis import ssd
     
     tf.enable_eager_execution()
+    tf.enable_v2_tensorshape()
     batch_size = 16
     image_size = 256
     use_dropout = False