fix publish url

Author: rwinch

buildSrc/src/main/java/org/springframework/gradle/maven/PublishLocalPlugin.java

@@ -20,7 +20,7 @@ public void execute(MavenPublishPlugin mavenPublish) {
 					@Override
 					public void execute(MavenArtifactRepository maven) {
 						maven.setName("local");
-						maven.setUrl(new File(project.getRootDir(), "publications/repos"));
+						maven.setUrl(new File(project.getRootProject().getBuildDir(), "publications/repos"));
 					}
 				});
 			}