fix query_patch for impediments: having a closing bracket now and excluding issues with parent_id

lib/backlogs_query_patch.rb

@@ -85,11 +85,12 @@ module Backlogs
                             sql << "(#{db_table}.id in (
                                   select issue_from_id
                                   from issue_relations ir
-                                  join issues blocked on
+                                  join issues blocked
+                                  on
                                     blocked.id = ir.issue_to_id
                                     and blocked.tracker_id in (#{all_trackers})
                                   where ir.relation_type = 'blocks'
-                                )"
+                                ) and #{db_table}.parent_id is NULL)"
                     end
                 }