[gptj] support older pytorch version
Unbreak 2 issues introduced by https://github.com/huggingface/transformers/pull/22069 . I validated that this version works even with pt-1.9, which is the new lowest version supported by transformers since https://github.com/huggingface/transformers/pull/22291

Fixes:



```
E             File "/mnt/nvme0/code/huggingface/transformers-master/examples/pytorch/language-modeling/run_clm.py", line 412, in main
E               model = AutoModelForCausalLM.from_pretrained(
E             File "/mnt/nvme0/code/huggingface/transformers-master/src/transformers/models/auto/auto_factory.py", line 470, in from_pretrained
E               model_class = _get_model_class(config, cls._model_mapping)
E             File "/mnt/nvme0/code/huggingface/transformers-master/src/transformers/models/auto/auto_factory.py", line 360, in _get_model_class
E               supported_models = model_mapping[type(config)]
E             File "/mnt/nvme0/code/huggingface/transformers-master/src/transformers/models/auto/auto_factory.py", line 602, in __getitem__
E               return self._load_attr_from_module(model_type, model_name)
E             File "/mnt/nvme0/code/huggingface/transformers-master/src/transformers/models/auto/auto_factory.py", line 616, in _load_attr_from_module
E               return getattribute_from_module(self._modules[module_name], attr)
E             File "/mnt/nvme0/code/huggingface/transformers-master/src/transformers/models/auto/auto_factory.py", line 561, in getattribute_from_module
E               if hasattr(module, attr):
E             File "/mnt/nvme0/code/huggingface/transformers-master/src/transformers/utils/import_utils.py", line 1109, in __getattr__
E               module = self._get_module(self._class_to_module[name])
E             File "/mnt/nvme0/code/huggingface/transformers-master/src/transformers/utils/import_utils.py", line 1121, in _get_module
E               raise RuntimeError(
E           RuntimeError: Failed to import transformers.models.gptj.modeling_gptj because of the following error (look up to see its traceback):
E           module 'torch' has no attribute 'fx'

```

credits for the fix: @mrwyattii

and:

```
E             File "/mnt/nvme0/code/huggingface/transformers-master/src/transformers/models/gptj/modeling_gptj.py", line 61, in create_sinusoidal_positions
E               return torch.concat((torch.sin(sinusoid_inp), torch.cos(sinusoid_inp)), dim=1)
E           AttributeError: module 'torch' has no attribute 'concat'
```

credits for the fix: @njhill
_The documentation is not available anymore as the PR was closed or merged._<|||||>Thank you for the quick review, Sylvain.<|||||>Thank you @stas00 @sgugger and sorry again for the breakage.<|||||>You haven't done anything wrong, Nick. It's just very difficult to instantly test all the different variations. We have more indepth multi-version CI running on a daily basis, so usually any missed problems get detected on the next day.

And thank you for your contribution!