d/ostree.maintscript: Clean up obsolete conffiles

These existed before we started removing what will eventually become
ostree-boot (see #824650).

debian/changelog

@@ -1,3 +1,11 @@
+ostree (2017.3-2) UNRELEASED; urgency=medium
+
+  * d/ostree.maintscript: Clean up obsolete conffiles from before we
+    started removing what will eventually become ostree-boot
+    (see #824650)
+
+ -- Simon McVittie <smcv@debian.org>  Mon, 10 Apr 2017 09:38:44 +0100
+
 ostree (2017.3-1) experimental; urgency=medium
 
   * d/watch, d/copyright: upstream project is now named libostree

debian/ostree.maintscript

@@ -0,0 +1,2 @@
+rm_conffile /etc/dracut.conf.d/ostree.conf 2016.5-3~ ostree
+rm_conffile /etc/grub.d/15_ostree 2016.5-3~ ostree