Fix Paper not detected sometimes

[LoneDev6]

Paper is not detected anymore because the removal of the class I used to check to identify if it is Paper.

[Andre601]

I personally suggest to look for the BuildInfo class and if found utilize that.
It provides useful info, including the server type (brand), which could allow a more accurate server type detection.

If it isn't there, chances are high it's Spigot or a Spigot fork (or in other cases an older version of Paper before the BuildInfo implementation).