Fix remove_concurrent_index down methods

db/migrate/20200312125121_add_index_on_active_and_template_and_type_and_id_to_services.rb

@@ -13,6 +13,6 @@ class AddIndexOnActiveAndTemplateAndTypeAndIdToServices < ActiveRecord::Migratio
   end
 
   def down
-    remove_concurrent_index :services, INDEX_NAME
+    remove_concurrent_index_by_name :services, INDEX_NAME
   end
 end

db/migrate/20200313123934_add_index_on_user_id_type_source_type_ldap_and_created_at_to_members.rb

@@ -13,6 +13,6 @@ class AddIndexOnUserIdTypeSourceTypeLdapAndCreatedAtToMembers < ActiveRecord::Mi
   end
 
   def down
-    remove_concurrent_index :members, INDEX_NAME
+    remove_concurrent_index_by_name :members, INDEX_NAME
   end
 end

db/migrate/20200323122201_add_index_on_user_and_created_at_to_ci_builds.rb

@@ -14,6 +14,6 @@ class AddIndexOnUserAndCreatedAtToCiBuilds < ActiveRecord::Migration[6.0]
   end
 
   def down
-    remove_concurrent_index :ci_builds, INDEX_NAME
+    remove_concurrent_index_by_name :ci_builds, INDEX_NAME
   end
 end