Update dependency com.github.spotbugs to v6.4.2

Author: renovate[bot]

gradle/libs.versions.toml

@@ -1,7 +1,7 @@
 [versions]
 sonarqube = '6.3.1.5724'
 jacocolog = '3.1.0'
-spotbugs = '6.4.1'
+spotbugs = '6.4.2'
 ben-manes-versions = '0.52.0'
 jgitver = '0.10.0-rc03'