Description of problem: This is to enhance user experience in the following scenarios: * one cannot delete a plugin and immediately upload a new version of it. This of course can be done without deleting the plugin at all, but if the users make the "mistake" of deleting the old version, they need to wait a couple of minutes before they can upload the new one. * one cannot upload a new version of a deleted plugin when one or more servers in HA is down. This is similar to the first bullet point but is made worse by the fact that the plugin WON'T be purged from the database until all servers in HA have "seen" it as deleted. This of course requires a running server. From a user perspective, it is not obvious why they would first need to start up a server before they can deploy a new version of a deleted plugin. Version-Release number of selected component (if applicable): 4.13.0-SNAPSHOT