Remove Docker Registry login.

Closes #1248.

Jenkinsfile

@@ -37,7 +37,6 @@ pipeline {
 
 			steps {
 				script {
-					docker.withRegistry(p['docker.registry'], p['docker.credentials']) {
 					docker.image(p['docker.java.main.image']).inside(p['docker.java.inside.docker']) {
 						sh "docker login --username ${DOCKER_HUB_USR} --password ${DOCKER_HUB_PSW}"
 						sh "PROFILE=ci,all-dbs ci/test.sh"
@@ -46,7 +45,6 @@ pipeline {
 				}
 			}
 		}
-		}
 
 		stage("Test other configurations") {
 			when {
@@ -69,7 +67,6 @@ pipeline {
 
 					steps {
 						script {
-							docker.withRegistry(p['docker.registry'], p['docker.credentials']) {
 							docker.image(p['docker.java.11.image']).inside(p['docker.java.inside.docker']) {
 								sh "docker login --username ${DOCKER_HUB_USR} --password ${DOCKER_HUB_PSW}"
 								sh "PROFILE=ci ci/test.sh"
@@ -78,7 +75,6 @@ pipeline {
 						}
 					}
 				}
-				}
 
 				stage("test: baseline (LTS)") {
 					agent {
@@ -93,7 +89,6 @@ pipeline {
 
 					steps {
 						script {
-							docker.withRegistry(p['docker.registry'], p['docker.credentials']) {
 							docker.image(p['docker.java.lts.image']).inside(p['docker.java.inside.docker']) {
 								sh "docker login --username ${DOCKER_HUB_USR} --password ${DOCKER_HUB_PSW}"
 								sh "PROFILE=ci ci/test.sh"
@@ -104,7 +99,6 @@ pipeline {
 				}
 			}
 		}
-		}
 
 		stage('Release to artifactory') {
 			when {
@@ -124,7 +118,6 @@ pipeline {
 
 			steps {
 				script {
-					docker.withRegistry(p['docker.registry'], p['docker.credentials']) {
 					docker.image(p['docker.java.main.image']).inside(p['docker.java.inside.basic']) {
 						sh 'MAVEN_OPTS="-Duser.name=jenkins -Duser.home=/tmp/jenkins-home" ./mvnw -s settings.xml -Pci,artifactory -Dmaven.repo.local=/tmp/jenkins-home/.m2/spring-data-jdbc-non-root ' +
 							'-Dartifactory.server=https://repo.spring.io ' +
@@ -139,7 +132,6 @@ pipeline {
 			}
 		}
 	}
-	}
 
 	post {
 		changed {