Don't show technical error message to the user

src/app/components/VoiceRoomItem.svelte

@@ -7,7 +7,6 @@
   import {isMobileViewport} from "@lib/html"
   import ProfileCircle from "@app/components/ProfileCircle.svelte"
   import RoomName from "@app/components/RoomName.svelte"
-  import {errorMessage} from "@lib/util"
   import {pushToast} from "@app/util/toast"
   import {
     deriveVoiceParticipants,
@@ -47,7 +46,7 @@
     try {
       await joinVoiceRoom(url, h, joinAbortController.signal)
     } catch (e) {
-      pushToast({theme: "error", message: `Failed to join voice room: ${errorMessage(e)}`})
+      pushToast({theme: "error", message: "Failed to join voice room"})
     } finally {
       isJoining = false
       joinAbortController = undefined