Remove duplicate postinst

debian/cosmic-greeter.postinst

@@ -7,7 +7,22 @@ set -e
 THIS_PACKAGE=cosmic-greeter
 DEFAULT_DISPLAY_MANAGER_FILE=/etc/X11/default-display-manager
 
-# debconf is not a registry, so we only fiddle with the default file if 
+# creating cosmic-greeter group if it isn't already there
+if ! getent group cosmic-greeter >/dev/null; then
+        addgroup --system --force-badname --quiet cosmic-greeter
+fi
+
+# creating cosmic-greeter user if it isn't already there
+if ! getent passwd cosmic-greeter >/dev/null; then
+        adduser --system --force-badname --quiet \
+            --ingroup cosmic-greeter \
+            --home /var/lib/cosmic-greeter --no-create-home \
+            --shell /bin/false \
+            cosmic-greeter
+        usermod -c "COSMIC Greeter" cosmic-greeter
+fi
+
+# debconf is not a registry, so we only fiddle with the default file if
 # the configure script requested an update
 if [ -e $DEFAULT_DISPLAY_MANAGER_FILE.debconf-update ]; then
   rm -f $DEFAULT_DISPLAY_MANAGER_FILE.debconf-update

debian/postinst

@@ -1,2 +0,0 @@
-#!/bin/bash
-useradd --groups video --no-create-home --system cosmic-greeter