Ungrouped session problem

[lystormenvoy]

Describe the problem:
[A clear and concise description of what the bug is.]

Ungrouped in Chinese is ‘未分组’ in this picture.

There are three ungrouped. In config.yaml they are different.

Some has no group properties:

  - name: 225全连接高校测试
    icon: fab fa-linux
    options:
      host: 192.168.37.225
      algorithms: {}
    id: ssh:custom:175:f20019c7-57b0-4327-a349-7372155daa0b
    type: ssh

Some has group properties but has no value:

  - name: 175安装测试
    icon: fab fa-linux
    options:
      host: 192.168.37.175
      port: 22
      user: root
      algorithms: {}
    group: 
    id: ssh:custom::b2d02a49-f3bd-4fa3-80fb-49c8dad06922
    type: ssh

Some has group properties but just with '' :

  - name: 190-ZLM
    icon: fab fa-linux
    options:
      host: 192.168.35.190
      port: 22
      user: root
      privateKeys: []
      forwardedPorts: []
      scripts: []
    group: ''
    id: ssh:custom::56364e9f-3bf2-411a-a589-e2e0eb651f86
    type: ssh

I think we should merge them in the same ungrouped group.

To Reproduce:
[Steps to reproduce the behavior]