[Java] Upgrade to sevntu-checks 1.21.1.

Author: mjpt777

build.gradle

@@ -116,7 +116,7 @@ subprojects {
 
  dependencies {
  checkstyle 'com.puppycrawl.tools:checkstyle:7.2'
- checkstyle 'com.github.sevntu.checkstyle:sevntu-checks:1.21.0'
+ checkstyle 'com.github.sevntu.checkstyle:sevntu-checks:1.21.1'
 
  testCompile 'org.hamcrest:hamcrest-all:1.3'
  testCompile 'junit:junit:4.12'