Update Checker incorrectly detects the server build

[Gaprix]

Issue description

When using the alpha build of the server (PM5), Update Checker detects it as a stable build.

• Expected result: Update Checker detects the alpha build of the server.
• Actual result: Update Checker shows a message that a stable build is being used.

Steps to reproduce the issue

1. Install the alpha build.
2. Set the preferred-channel parameter to "alpha" in pocketmine.yml.
3. Start the server.
4. A message appears in the log that a stable build is being used.

OS and versions

• PocketMine-MP: 5.0.0-ALPHA6 (git hash: da4315d)
• PHP: 8.0.25
• Server OS: Linux

Plugins

None.

Crashdump, backtrace or other files

https://pastebin.com/h8Ht8fWc

[dktapps]

This happens because VersionInfo::IS_DEVELOPMENT_BUILD is used to determine whether the channel should be stable or not. This is incorrect, because any released build has IS_DEVELOPMENT_BUILD=false, but is not necessarily stable.

Two possible solutions:

• Use VersionInfo::BUILD_CHANNEL instead
• Remove these warnings entirely. It's questionable what benefit they really offer anyway.