TransferResource.getRepositoryUrl is documented to end in a slash if known, so...

TransferResource.getRepositoryUrl is documented to end in a slash if known, so we should not add one.
Parsing POMs
Downloaded artifact http://repo.jenkins-ci.org/public//org/jenkins-ci/plugins/plugin/1.456/plugin-1.456.pom
Downloaded artifact http://repo.jenkins-ci.org/public//org/jenkins-ci/jenkins/1.26/jenkins-1.26.pom

maven-plugin/src/main/resources/hudson/maven/Messages.properties

@@ -40,7 +40,7 @@ MavenModuleSet.readResolve_updateConfigProvider=ERROR: Please update the 'config
 PluginImpl.updateConfiProvider=The current installed version of 'config-file-provider' is not compatible with this core anymore (requires >= 2.3)
 
 MavenModuleSetBuild.DiscoveredModule=Discovered a new module {0} {1}
-MavenModuleSetBuild.DownloadedArtifact=Downloaded artifact {0}/{1}
+MavenModuleSetBuild.DownloadedArtifact=Downloaded artifact {0}{1}
 MavenModuleSetBuild.FailedToParsePom=Failed to parse POMs
 MavenModuleSetBuild.FailedToTransfer=Failed to transfer {0}
 MavenModuleSetBuild.FoundModuleWithoutProject=Found a module with path {0} but no associated project