d/ostree-boot.postinst: Trigger an update of the initramfs

Otherwise the dracut initramfs won't be rebuilt to include ostree-boot.

debian/changelog

@@ -1,14 +1,16 @@
 ostree (2019.3-2) UNRELEASED; urgency=medium
 
-  [ Simon McVittie ]
-  * Switch packaging branch to debian/experimental
-
   [ Felix Krull ]
   * Enable ostree-boot package (Closes: #824650)
   * ostree-boot: Weaken dracut Depends to Recommends.
     The systemd parts of the package could also be used for integration
     with e.g. initramfs-tools.
 
+  [ Simon McVittie ]
+  * Switch packaging branch to debian/experimental
+  * d/ostree-boot.postinst: Trigger an update of the initramfs.
+    Otherwise the dracut initramfs won't be rebuilt to include ostree-boot.
+
  -- Simon McVittie <smcv@debian.org>  Fri, 23 Aug 2019 09:03:04 +0100
 
 ostree (2019.3-1) unstable; urgency=medium

debian/ostree-boot.postinst

@@ -0,0 +1,11 @@
+#!/bin/sh
+
+set -e
+
+case "$1" in
+    (configure)
+        dpkg-trigger --no-await update-initramfs
+        ;;
+esac
+
+#DEBHELPER#