Is installer.template.php a backdoor?

I just got an automated email from Dreamhost saying that they had detected installer.template.php to be a threat.

Specifically, they said

The existence of these pages on your website(s) is likely a sign you have been compromised.

So they think this file is very bad. I can say that the file is probably there because I used Duplicator, though.

So is the file in question a hazard? In the final steps of the Duplicator Installer, I ran “Delete Install Files,” I’m pretty sure. I don’t see installer.php, installer-data.sql, installer-log.txt or the package on my site, which is evidence that the deletion occurred. So either installer.template.php should have been deleted too, or Dreamhost is mistaken that this was a threat. Which is it?

(I did see an installer folder still, which included a file called main.installer.php though).

Thank you so much for your advice and for this very useful plugin.

http://ww.wp.xz.cn/plugins/duplicator/