tacotron2.yaml config file buggy
**Describe the bug**
When initiating tacotron.py for training, the following error comes up:

Error executing job with overrides: []
Error in call to target 'nemo.collections.tts.data.tts_dataset.TTSDataset':
FileNotFoundError(2, 'No such file or directory')
full_key: train_ds.dataset

**Steps/Code to reproduce bug**

python tacotron2.py

(hardcoded the training and validation dataset paths in tacotron2.yaml file but also tried giving the path from the cli)

**Expected behavior**

Training starts.

**Environment overview (please complete the following information)**

 - Environment location: on-site desktop
 - Method of NeMo install: tries installing both with pip and from source.
 - If method of install is [Docker], provide `docker pull` & `docker run` commands used

**Environment details**

If NVIDIA docker image is used you don't need to specify these.
Otherwise, please provide:
- OS version: Ubuntu 20.04 and Windows 11 (dual-boot)
- PyTorch version: 1.13.1
- Python version: 3.8.0

**Additional context**

Add any other context about the problem here.
Example: GPU model
