Revert "Enable a second build using Java 8, to ensure backward compatibility"
Revert "Enable a second build using Java 8, to ensure backward compatibility"

This reverts commit d4839aaa8c7cbbe1073124208e6e975f72a4aa3a.

GlowstonePlusPlus/GlowstonePlusPlus,GlowstoneMC/GlowstonePlusPlus,GlowstonePlusPlus/GlowstonePlusPlus,GlowstoneMC/GlowstonePlusPlus,GlowstonePlusPlus/GlowstonePlusPlus,GlowstoneMC/GlowstonePlusPlus,GlowstonePlusPlus/GlowstonePlusPlus,GlowstoneMC/GlowstonePlusPlus