Adds further condition in DmsfQuery#dmsf_nodes

It will make sure that a pending link will be
deleted from the query and hence not displayed
to the user.

A pending link has no project assigned. For those
links the case statement in DmsfQuery#dmsf_nodes
will now return true what causes the link to be
deleted from the query result.

app/models/dmsf_query.rb

@@ -232,6 +232,8 @@ class DmsfQuery < Query
             !dmsf_link.dmsf_folder.visible? || !DmsfFolder.permissions?(dmsf_link.dmsf_folder, allow_system: false)
           elsif dmsf_link.project
             !dmsf_link.project.dmsf_available?
+          else
+            !dmsf_link.project&.dmsf_available?
           end
         else
           false