PEP 8 whitespace cleanup. (#20783)

* PEP 8 E271 whitespace cleanup.
* PEP 8 W293 whitespace cleanup.
* Fix whitespace issue from recent PR.

lib/ansible/modules/cloud/amazon/rds.py

@@ -280,7 +280,7 @@ EXAMPLES = '''
     command: reboot
     instance_name: database
     wait: yes
-    
+
 # Restore a Postgres db instance from a snapshot, wait for it to become available again, and
 #  then modify it to add your security group. Also, display the new endpoint.
 #  Note that the "publicly_accessible" option is allowed here just as it is in the AWS CLI
@@ -298,7 +298,7 @@ EXAMPLES = '''
      tags:
          Name: pg1_test_name_tag 
   register: rds
-  
+
 - local_action:
      module: rds
      command: modify
@@ -844,7 +844,7 @@ def promote_db_instance(module, conn):
     valid_vars = ['backup_retention', 'backup_window']
     params = validate_parameters(required_vars, valid_vars, module)
     instance_name = module.params.get('instance_name')
-    
+
     result = conn.get_db_instance(instance_name)
     if not result:
         module.fail_json(msg="DB Instance %s does not exist" % instance_name)