No coloring in Declarative Pipeline since 0.7.0

[twz123]

Please provide precise details of the issue you detected.

Test environment

• Jenkins Version: 2.222.4
• AnsiColor Version: 0.7.0
• Hostsystem: official Docker image jenkins/jenkins:2.222.4

Expected behavior

What did you expect the plugin to do?

Behave as v0.6.3 did:

Actual behavior

What did the plugin do instead?

ANSI control characters are shown, no colors.

Steps to reproduce the behavior

Run this Pipeline on Jenkins 2.222.4 with ansicolor 0.7.0

pipeline {
  agent none

  options {
    ansiColor('xterm')
  }

   stages {
      stage('Hello') {
         steps {
            echo '\u001B[31mI am red, hopefully!\u001B[0m'
         }
      }
   }
}

[twz123]

Dupe of #185