Add multiple URLs to the Maven property of a gradle

This is a mistake

repositories {
    mavenCentral()
    maven {
        url "http://maven.springframework.org/release"
        url "http://maven.restlet.org"
    }
}

The right way to do it:

repositories {
  maven { url "http://maven.springframework.org/release" }
  maven { url "https://maven.fabric.io/public" }
}