Add Mask Passwords to the managed set

[basil]

This is almost trivial, but the following test failure remains:

[ERROR] com.michelin.cio.hudson.plugins.maskpasswords.MaskPasswordsWorkflowTest.basics -- Time elapsed: 8.022 s <<< FAILURE!
java.lang.AssertionError: TODO cannot keep it out of the closure block, but at least outside users cannot see this; withCredentials does better expected:<[workflow/5.xml, program.dat, build.xml]> but was:<[atomic3284189733458177651.tmp, build.xml, program.dat, workflow/5.xml]>
        at org.junit.Assert.fail(Assert.java:89)
        at org.junit.Assert.failNotEquals(Assert.java:835)
        at org.junit.Assert.assertEquals(Assert.java:120)
        at com.michelin.cio.hudson.plugins.maskpasswords.MaskPasswordsWorkflowTest.lambda$basics$3(MaskPasswordsWorkflowTest.java:120)
        at org.jvnet.hudson.test.RestartableJenkinsRule$3.evaluate(RestartableJenkinsRule.java:234)
        at org.jvnet.hudson.test.RestartableJenkinsRule$6.evaluate(RestartableJenkinsRule.java:282)
        at org.jvnet.hudson.test.JenkinsRule$1.evaluate(JenkinsRule.java:659)
        at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:317)
        at java.base/java.lang.Thread.run(Thread.java:1583)