Compacting array building logic

This commit serves two purposes:

1) First, and most important, it fixes #4833
2) Second, it unifies the logic for determining the ids

More on 4833 (in case you don't have access to Github)

The observed error is as follows:

> Depositing a work with past embargo gives no id error
>
> Depositing a work with an embargo date in the past gives an "No ID
> provided for ActiveFedora::Base" error.
>
> Expected Behavior: Depositing a work with a past embargo should fail
> to be created and entered information should be preserved

In debugging the application, the `@object.member_of_collection_ids` was
the following: `["", "admin_set/default"]`

That appears to come from the form submitting a select box that has no
selected value (e.g., the `""` value).  I verified this logic change by
UI interaction.

app/services/hyrax/edit_permissions_service.rb

@@ -183,13 +183,7 @@ def object_unauthorized_collection_ids
     # find all of the collection ids an object is a member of
     # @return [Array] array of collection ids
     def object_member_of_ids
-      @object_member_of_ids ||= begin
-                              belongs_to = []
-                              # get all of work's collection ids from the form
-                              belongs_to += @object.member_of_collection_ids
-                              belongs_to << @object.admin_set_id if @object.admin_set_id.present?
-                              belongs_to
-                            end
+      @object_member_of_ids ||= (@object.member_of_collection_ids + [@object.admin_set_id]).select(&:present?)
     end
 
     # The list of all collections this user has manage rights on