GithubMetaAnalyzer ignore repositoryUrl if repositoryPassword is empty

### Current Behavior

`GithubMetaAnalyzer` still calls github.com even if a proxy URL is set in Administration > Repositories > GitHub

Note: unless a password is set
https://github.com/DependencyTrack/dependency-track/blob/4.13.0/src/main/java/org/dependencytrack/tasks/repositories/GithubMetaAnalyzer.java#L124

### Steps to Reproduce

1. In Administration > Repositories > GitHub, replace URL `https://github.com` with another URL. Do not set password
2. Let `GithubMetaAnalyzer` run
3. It fails because github.com is not reachable

### Expected Behavior

Would use URL provided in settings

### Dependency-Track Version

4.13.6

### Dependency-Track Distribution

Container Image

### Database Server

PostgreSQL

### Database Server Version

_No response_

### Browser

Mozilla Firefox

### Checklist

- [x] I have read and understand the [contributing guidelines](https://github.com/DependencyTrack/dependency-track/blob/master/CONTRIBUTING.md#filing-issues)
- [x] I have checked the [existing issues](https://github.com/DependencyTrack/dependency-track/issues) for whether this defect was already reported