fix/adapt argument name for pretrained model

[linakrisztian]

When using pretrained models within trainig I experienced the --weights_path was not implemented anymore. I guess the name was just changed, so this small change should solve it.

[pesekon2]

@linakrisztian You are right, it is surely a bug (here we can see that I do not fine-tune often enough as the bug is in the code for quite some time). However, if you don't mind, I would like to keep the parameter name still weights_path and instead got rid of the model_path parameter check (-> weights_path). The reasons are two:

1. The *.h5 file, no information on the model structure (connections) is written, as far as I know; it contains just values for all weights.
2. It could bring some confusion when used together with model_fn and output_path (is model_path the output one or is it the one I am loading? Or is that model_fn)? A counter-argument: The naming of the parameters is stupid in general and things like model_fn should be renamed.

Or do you think that model_path is more understandable for the parameter? In such case, I would have no problem accepting the change.

[linakrisztian]

No you are right, I would agree on that. weights_path is more understandable. I changed it accordingly.

[pesekon2]

Great, thank you.