Update dependency com.google.mug:mug to v5.6

Author: renovate-bot

build.gradle

@@ -36,7 +36,7 @@ dependencies {
     implementation 'com.github.zhanhb:thymeleaf-layout-dialect:2.5.3'
     implementation 'com.github.spotbugs:spotbugs-annotations:4.4.1'
     implementation 'com.google.guava:guava:31.0.1-jre'
-    implementation 'com.google.mug:mug:5.5'
+    implementation 'com.google.mug:mug:5.6'
     implementation 'com.hierynomus:sshj:0.31.0'
     implementation 'org.postgresql:postgresql'
     runtimeOnly 'org.flywaydb:flyway-core'