DRY: Remove default parameter value handeling in __apt_source

cdist/conf/type/__cdistmarker/gencode-remote

@@ -19,19 +19,11 @@
 #
 
 # The marker file is established in the docs, but it isn't obligatory.
-if [ -f "$__object/parameter/destination" ]; then
 destination="$(cat "$__object/parameter/destination")"
-else
-    destination='/etc/cdist-configured'
-fi
 
 # The basic output of date is usually good enough, but variety is the
 #   spice of life...
-if [ -f "$__object/parameter/format" ]; then
 format="$(cat "$__object/parameter/format")"
-else
-    format='-u'
-fi
 
 # Dump the timestamp in UTC to the marker
 echo "date $format > $destination"

cdist/conf/type/__cdistmarker/parameter/default/destination

@@ -0,0 +1 @@
+/etc/cdist-configured

cdist/conf/type/__cdistmarker/parameter/default/format

@@ -0,0 +1 @@
+-u