fix build error when using java 8

Author: AntonUden

NovaCore-Spigot-Abstraction-1_16-plus-shared/pom.xml

@@ -86,7 +86,7 @@
 		<dependency>
 			<groupId>com.mojang</groupId>
 			<artifactId>authlib</artifactId>
-			<version>3.13.56</version>
+			<version>1.5.21</version>
 			<scope>provided</scope>
 		</dependency>
 	</dependencies>