Revert "Gradle 6.3"

This reverts commit 76e6440

Author: elizarov

gradle/wrapper/gradle-wrapper.properties

@@ -6,4 +6,4 @@ distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-6.3-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-5.6.1-all.zip