Dependency-Check crashes when adding dataMirror URL

Hi There,

We're having a local data mirror which works great with mvn analyzer. Now I'm working with the dependency-check-build-task but it crashes after adding dataMirror URL.

```yaml
- task: dependency-check-build-task@6
inputs:
projectName: "Frontend"
scanPath: "$(Build.Repository.LocalPath)/**/*"
format: "HTML, JSON, JUNIT"
additionalArguments: "--disableYarnAudit --nodeAuditSkipDevDependencies --nodePackageSkipDevDependencies
dataMirror: 'http://1.2.3.4"'
```

```
Downloading Dependency Check data cache archive...
Downloading ZIP from "http://1.2.3.4"...
EISDIR: illegal operation on a directory, open '/opt/build-agent/_work/_tasks/dependency-check-build-task_47ea1f4a-57ba-414a-b12e-c44f42765e72/6.0.4'
##[error]EISDIR: illegal operation on a directory, open '/opt/build-agent/_work/_tasks/dependency-check-build-task_47ea1f4a-57ba-414a-b12e-c44f42765e72/6.0.4'
##[error]Unhandled error condition detected.

```

Start with the dependency-check-build-task@6 handling of the dataMirror input and reproduce the crash using the YAML configuration and mirror URL shown in the issue. Done means the task accepts the dataMirror URL without the EISDIR error and proceeds with the dependency scan.

Written by the indexing model from the issue text.