Describe the bug
When the denominator of the generalized dice score metric is zero, i.e., the ground-truth is empty, score should be 1 if the prediction is also empty and 0 otherwise. Right now, the output score is always 1.

To Reproduce

>>> from monai.metrics import GeneralizedDiceScore, compute_generalized_dice
>>> import torch
>>> pred = torch.ones((1, 1, 3, 3))
>>> target = torch.zeros((1, 1, 3, 3))
>>> compute_generalized_dice(pred, target)
tensor([1.])

Expected behavior
Since the prediction is not empty, the score should be 0.

Environment

================================
Printing MONAI config...

MONAI version: 0.9.0+0.gaf0e0e9f.dirty
Numpy version: 1.22.3
Pytorch version: 1.11.0
MONAI flags: HAS_EXT = False, USE_COMPILED = False
MONAI rev id: af0e0e9
MONAI file: /home/joao/MONAI/monai/init.py

Optional dependencies:
Pytorch Ignite version: 0.4.8
Nibabel version: 3.2.2
scikit-image version: 0.19.2
Pillow version: 9.0.1
Tensorboard version: 2.9.0
gdown version: 4.4.0
TorchVision version: 0.12.0
tqdm version: 4.64.0
lmdb version: 1.3.0
psutil version: 5.9.1
pandas version: 1.4.2
einops version: 0.4.1
transformers version: 4.19.2
mlflow version: 1.26.1
pynrrd version: 0.4.3

For details about installing the optional dependencies, please visit:
https://docs.monai.io/en/latest/installation.html#installing-the-recommended-dependencies

================================
Printing system config...

System: Linux
Linux version: Ubuntu 20.04.3 LTS
Platform: Linux-5.10.102.1-microsoft-standard-WSL2-x86_64-with-glibc2.31
Processor: x86_64
Machine: x86_64
Python version: 3.10.4
Process name: python
Command: ['python', '-c', 'import monai; monai.config.print_debug_info()']
Open files: []
Num physical CPUs: 6
Num logical CPUs: 6
Num usable CPUs: 6
CPU usage (%): [5.1, 3.6, 4.1, 3.6, 4.1, 100.0]
CPU freq. (MHz): 3600
Load avg. in last 1, 5, 15 mins (%): [0.8, 1.0, 1.3]
Disk usage (%): 20.6
Avg. sensor temp. (Celsius): UNKNOWN for given OS
Total physical memory (GB): 11.7
Available memory (GB): 10.0
Used memory (GB): 1.4

================================
Printing GPU config...

Num GPUs: 1
Has CUDA: True
CUDA version: 11.3
cuDNN enabled: True
cuDNN version: 8200
Current device: 0
Library compiled for CUDA architectures: ['sm_37', 'sm_50', 'sm_60', 'sm_61', 'sm_70', 'sm_75', 'sm_80', 'sm_86', 'compute_37']
GPU 0 Name: NVIDIA GeForce GTX 1060 3GB
GPU 0 Is integrated: False
GPU 0 Is multi GPU board: False
GPU 0 Multi processor count: 9
GPU 0 Total memory (GB): 3.0
GPU 0 CUDA capability (maj.min): 6.1

Additional context
I'm the author of the PR that introduced this metric, so the mistake is on me. Sorry guys! Will make a PR for a fix right away