ConfigurationPropertyName equals method fails when values start the same

[philwebb]

Raised by @spencergibb in a Spring Cloud originally but ultimately the problem is in ConfigurationPropertyName as shown by the following test:

    @Test
    public void equalsWhenStartsWith() {
        ConfigurationPropertyName n1 = ConfigurationPropertyName.of("my.sources[0].xame");
        ConfigurationPropertyName n2 = ConfigurationPropertyName
                .of("my.sources[0].xamespace");
        assertThat(n1).isNotEqualTo(n2);
    }