Fix plugin unregister: unload all modules.

server/main.ts

@@ -1,5 +1,9 @@
 import { initSettings } from './lib/settings'
 import { initRouters } from './lib/routers'
+import type { Logger } from 'winston'
+
+const decache = require('decache')
+let logger: Logger | undefined
 
 async function register ({
   registerSetting,
@@ -7,6 +11,8 @@ async function register ({
   getRouter,
   peertubeHelpers
 }: RegisterServerOptions): Promise<any> {
+  logger = peertubeHelpers.logger
+
   await initSettings({ registerSetting })
   await initRouters({
     settingsManager,
@@ -16,6 +22,10 @@ async function register ({
 }
 
 async function unregister (): Promise<any> {
+  const module = __filename
+  logger?.info(`Unloading module ${module}...`)
+  decache(module)
+  logger?.info(`Successfully unloaded the module ${module}`)
 }
 
 module.exports = {