make sure that no http requests are done inside of /sync

lib/encryption/encryption.dart

@@ -72,12 +72,16 @@ class Encryption {
   }
 
   Future<void> handleToDeviceEvent(ToDeviceEvent event) async {
-    if (['m.room_key', 'm.room_key_request', 'm.forwarded_room_key']
+    if (event.type == 'm.room_key') {
-        .contains(event.type)) {
+      // a new room key. We need to handle this asap, before other
-      // a new room key or thelike. We need to handle this asap, before other
       // events in /sync are handled
       await keyManager.handleToDeviceEvent(event);
     }
+    if (['m.room_key_request', 'm.forwarded_room_key'].contains(event.type)) {
+      // "just" room key request things. We don't need these asap, so we handle
+      // them in the background
+      unawaited(keyManager.handleToDeviceEvent(event));
+    }
     if (event.type.startsWith('m.key.verification.')) {
       // some key verification event. No need to handle it now, we can easily
       // do this in the background

lib/encryption/key_manager.dart

@@ -123,6 +123,8 @@ class KeyManager {
       json.encode(content),
       json.encode({}),
     );
+    // Note to self: When adding key-backup that needs to be unawaited(), else
+    // we might accidentally end up with http requests inside of the sync loop
     // TODO: somehow try to decrypt last message again
     final room = client.getRoomById(roomId);
     if (room != null) {