title: Restore maven plugin for a project on eclipse
body: <p>I've disabled m2eclipse plugin for a project by clicking on "Disable Maven Nature" as shown in the Figure below. Then the Maven entry disappeared from the menu and I'm unable to restore it.</p>
  
  <p><img src="https://i.stack.imgur.com/QEQwv.png" alt="enter image description here"></p>
  
  <p>How do I restore/reset/re-enable so that the entry appears again?</p>
  
  <p>PS 1: I'd like to do that without re-importing the project.</p>
  
  <p>PS 2: I've looked in <code>${WORKSPACE}/.metadata\.plugins\org.eclipse.m2e.core.ui</code> and <code>${WORKSPACE}/.metadata\.plugins\org.eclipse.m2e.core</code> but nothing seems related.</p>