Update Readme to Change Bugtracker URL

Updated the VideoLAN Gitlab bugtracker URL in README.md

Description

Earlier, the URL was set as https://code.videolan.org/videolan/vlc-android/issues but the correct URL is https://code.videolan.org/videolan/vlc-android/-/issues

Motivation and Context

I was trying to access the bugtracker and I was stuck since my browser wasn't redirecting the link to open the new one which includes a hyphen.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Enhancement (non-breaking change which cleans up / improves existing functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• I have read the CONTRIBUTING section of the README document.

Resolves

Fixes: #1427 (closed)