message: fix model.compile docstring to match Keras
  `loss_weights` should be either a list or a dict, not a tensor
diff: @@ -256,7 +256,7 @@ class Model(network.Network, version_utils.VersionSelector):
  will then be the *weighted sum* of all individual losses,
  weighted by the `loss_weights` coefficients.
  If a list, it is expected to have a 1:1 mapping
  - to the model's outputs. If a tensor, it is expected to map
  + to the model's outputs. If a dict, it is expected to map
  output names (strings) to scalar coefficients.
  sample_weight_mode: If you need to do timestep-wise
  sample weighting (2D weights), set this to `"temporal"`.
  