Update Dockerfile for sqlite3, update models for cascade delete, fix backup schedule

server/managers/EmailManager.js

@@ -1,4 +1,5 @@
 const nodemailer = require('nodemailer')
+const Database = require('../Database')
 const Logger = require("../Logger")
 
 class EmailManager {

server/managers/PlaybackSessionManager.js

@@ -52,6 +52,7 @@ class PlaybackSessionManager {
       }
     }
 
+    await Database.createDevice(deviceInfo)
 
     return deviceInfo
   }
@@ -221,9 +222,6 @@ class PlaybackSessionManager {
       newPlaybackSession.audioTracks = audioTracks
     }
 
-    // Will save on the first sync
-    user.currentSessionId = newPlaybackSession.id
-
     this.sessions.push(newPlaybackSession)
     SocketAuthority.adminEmitter('user_stream_update', user.toJSONForPublic(this.sessions, Database.libraryItems))