title: git - error after changing submodules URL - fatal: Needed a single revision
body: <p>I downloaded a module from github. But instead of using the github repository, I initialized my own and pushed all the code to my own bitbucket remote repository with one "initial commit".</p>
  
  <p>But I would like to use the github repo, so that it is easier to keep it up to date. So I opened <code>.gitmodules</code> and changed the URL of the repo, made a commit and pushed.</p>
  
  <p>But if I execute <code>git clone myrepo_url.git</code> and then execute <code>git submodule --init --update --remote</code> then everything is fine, but the module where I changed the URL.</p>
  
  <pre><code>&gt; fatal: Needed a single revision, unable to find commit of
  &gt; origin/master in Submodul-path 'app/code/EthanYehuda/CronjobManager'
  </code></pre>
  
  <p>Thats maybe because my old repository used <code>master</code> as the main branch and the github repository uses <code>1.x</code>.</p>
  
  <p><strong>.git/modules/app/code/EthanYehuda/CronjobManager/config</strong>:</p>
  
  <pre><code>[core]
          repositoryformatversion = 0
          filemode = true
          bare = false
          logallrefupdates = true
          worktree = ../../../../../../app/code/EthanYehuda/CronjobManager
  [remote "origin"]
          url = https://github.com/Ethan3600/magento2-CronjobManager.git
          fetch = +refs/heads/*:refs/remotes/origin/*
  [branch "1.x"]
          remote = origin
          merge = refs/heads/1.x
  </code></pre>
  
  <p><strong>.gitmodules</strong></p>
  
  <pre><code>[submodule "app/code/EthanYehuda/CronjobManager"]
          path = app/code/EthanYehuda/CronjobManager
          url = https://github.com/Ethan3600/magento2-CronjobManager.git
  </code></pre>
  
  <p>How can I fix this so that the error does not show if I clone the project?</p>