Fix minor pathological cases

src/main/kotlin/mdnet/base/MangaDexClient.kt

@@ -45,16 +45,17 @@ import java.util.concurrent.atomic.AtomicBoolean
 class ClientSettingsException(message: String) : Exception(message)
 
 class MangaDexClient(private val settingsFile: File, databaseFile: File, cacheFolder: File) {
-    // just for scheduling one task, so single-threaded
+    // this must remain single-threaded because of how the state mechanism works
     private val executor = Executors.newSingleThreadScheduledExecutor()
-    private val isReloading = AtomicBoolean(false)
 
     private val database: Database
     private val cache: DiskLruCache
     private var settings: ClientSettings
 
+    // state that must only be accessed from the thread on the executor
     private var imageServer: ServerManager? = null
     private var webUi: Http4kServer? = null
+    // end protected state
 
     init {
         settings = try {
@@ -145,6 +146,7 @@ class MangaDexClient(private val settingsFile: File, databaseFile: File, cacheFo
     }
 
     fun shutdown() {
+        executor.schedule({
             LOGGER.info { "Mangadex@Home Client shutting down" }
             if (webUi != null) {
                 stopWebUi()
@@ -159,6 +161,7 @@ class MangaDexClient(private val settingsFile: File, databaseFile: File, cacheFo
             } catch (e: IOException) {
                 LOGGER.error(e) { "Cache failed to close" }
             }
+        }, 0, TimeUnit.SECONDS)
     }
 
     /**

src/main/kotlin/mdnet/base/ServerManager.kt

@@ -37,7 +37,7 @@ class ServerManager(serverSettings: ServerSettings, devSettings: DevSettings, ma
     // this must remain single-threaded because of how the state mechanism works
     private val executor = Executors.newSingleThreadScheduledExecutor()
 
-    // state that must only be accessed from the thread on the executorService
+    // state that must only be accessed from the thread on the executor
     private var state: State
     private var serverHandler: ServerHandler
     // end protected state