fix: WADO-URI's storeParh incorrect

# Problem
- `storeParh` need to append slash in `DICOM_STORE_ROOTPATH` env
- If not appned, it will get `rootfiles/item`,
but correct is `root/files/item`

# Solution
- Use `path.join` instead string concat

api/dicom/controller/wado.js

@@ -21,7 +21,8 @@ module.exports = async(req, res) =>
         if (!oriPath) {
             return dicomWebHandleError.sendNotFoundMessage(req , res);
         }
-        let storePath = `${disk}${oriPath}`;
+
+        let storePath = path.join(disk, oriPath);
         if (!fs.existsSync(storePath)) {
             return dicomWebHandleError.sendNotFoundMessage(req , res);
         }