Try to fix multi-gpu training issue in tumor-detection (#686)

Fixes #685


### Status
**Ready/Work in progress/Hold**

### Please ensure all the checkboxes:
<!--- Put an `x` in all the boxes that apply, and remove the not
applicable items -->
- [x] Codeformat tests passed locally by running `./runtests.sh
--codeformat`.
- [ ] In-line docstrings updated.
- [ ] Update `version` and `changelog` in `metadata.json` if changing an
existing bundle.
- [ ] Please ensure the naming rules in config files meet our
requirements (please refer to: `CONTRIBUTING.md`).
- [ ] Ensure versions of packages such as `monai`, `pytorch` and `numpy`
are correct in `metadata.json`.
- [ ] Descriptions should be consistent with the content, such as
`eval_metrics` of the provided weights and TorchScript modules.
- [ ] Files larger than 25MB are excluded and replaced by providing
download links in `large_file.yml`.
- [ ] Avoid using path that contains personal information within config
files (such as use `/home/your_name/` for `"bundle_root"`).

---------

Signed-off-by: YunLiu <[email protected]>

models/pathology_tumor_detection/configs/metadata.json

@@ -1,7 +1,8 @@
 {
     "schema": "https://github.com/Project-MONAI/MONAI-extra-test-data/releases/download/0.8.1/meta_schema_20220324.json",
-    "version": "0.6.0",
+    "version": "0.6.1",
     "changelog": {
+        "0.6.1": "fix multi-gpu issue",
         "0.6.0": "use monai 1.4 and update large files",
         "0.5.9": "update to use monai 1.3.1",
         "0.5.8": "update readme to add memory warning",

models/pathology_tumor_detection/configs/train.json

@@ -196,6 +196,11 @@
             ]
         },
         "handlers": [
+            {
+                "_target_": "LrScheduleHandler",
+                "lr_scheduler": "@lr_scheduler",
+                "print_lr": true
+            },
             {
                 "_target_": "ValidationHandler",
                 "validator": "@validate#evaluator",
@@ -207,11 +212,6 @@
                 "tag_name": "train_loss",
                 "output_transform": "$monai.handlers.from_engine(['loss'], first=True)"
             },
-            {
-                "_target_": "LrScheduleHandler",
-                "lr_scheduler": "@lr_scheduler",
-                "print_lr": true
-            },
             {
                 "_target_": "TensorBoardStatsHandler",
                 "log_dir": "@output_dir",