Upgrade to Shadow 8.1.1.

Author: vyazelenko

build.gradle

@@ -20,7 +20,7 @@ import java.security.MessageDigest
 
 plugins {
  id 'java-library'
- id 'com.github.johnrengelman.shadow' version '7.1.2' apply false
+ id 'com.github.johnrengelman.shadow' version '8.1.1' apply false
  id 'com.github.ben-manes.versions' version '0.46.0'
 }