fix (#195) & opt.

- fix: debug provider color
- fix: can't write script through SFTP (#195)
- opt.: go next refresh only after current refresh task is done

lib/data/model/server/server.dart

@@ -10,9 +10,8 @@ class Server implements TagPickable {
   SSHClient? client;
   ServerState state;
 
-  /// Whether is generating client.
-  /// Use this to avoid reconnecting if last connect try not finished.
-  bool isGenerating = false;
+  /// Whether is connectting, parsing and etc.
+  bool isBusy = false;
 
   Server(this.spi, this.status, this.client, this.state);