Add local_files_only parameter to pretrained items (#2930)

* Add disable_outgoing to pretrained items

Setting disable_outgoing=True disables outgonig traffic:
- etags are not looked up
- models are not downloaded

* parameter name change

* Remove forgotten print

src/transformers/modeling_utils.py

@@ -376,6 +376,7 @@ class PreTrainedModel(nn.Module, ModuleUtilsMixin):
         resume_download = kwargs.pop("resume_download", False)
         proxies = kwargs.pop("proxies", None)
         output_loading_info = kwargs.pop("output_loading_info", False)
+        local_files_only = kwargs.pop("local_files_only", False)
 
         # Load config if we don't provide a configuration
         if not isinstance(config, PretrainedConfig):
@@ -388,6 +389,7 @@ class PreTrainedModel(nn.Module, ModuleUtilsMixin):
                 force_download=force_download,
                 resume_download=resume_download,
                 proxies=proxies,
+                local_files_only=local_files_only,
                 **kwargs,
             )
         else:
@@ -435,6 +437,7 @@ class PreTrainedModel(nn.Module, ModuleUtilsMixin):
                     force_download=force_download,
                     proxies=proxies,
                     resume_download=resume_download,
+                    local_files_only=local_files_only,
                 )
             except EnvironmentError:
                 if pretrained_model_name_or_path in cls.pretrained_model_archive_map: