Fix typo in train_dreambooth_inpaint (huggingface#1885)

Fix typo in train_dreambooth_inpaint.

Author: pcuenca

examples/research_projects/dreambooth_inpaint/train_dreambooth_inpaint.py

@@ -672,7 +672,7 @@ def collate_fn(examples):
     progress_bar = tqdm(range(global_step, args.max_train_steps), disable=not accelerator.is_local_main_process)
     progress_bar.set_description("Steps")
 
-    for epoch in range(first_epoch, args.num_epochs):
+    for epoch in range(first_epoch, args.num_train_epochs):
         unet.train()
         for step, batch in enumerate(train_dataloader):
             # Skip steps until we reach the resumed step