Unhandled exception: AttributeError: 'ConfigPlugin' object has no attribute 'getCmdlineValue'

### Step 1: Please describe your environment

* ZeroNet version: 0.7.1
* Operating system: Windows 10
* Web browser: Google Chrome
* Tor status: not available
* Opened port: no
* Special configuration: ____

### Step 2: Describe the problem:
Error when opening zeronet client after trying to update.
#### Steps to reproduce:

1. when starting zeronet click update py3 quickly
2. click on update even if it's green background
3. probably fail to open zeronet again

#### Observed Results:

* What happened? This could be a screenshot, a description, log output (you can send log/debug.log file to hello@zeronet.io if necessary), etc.

#### Expected Results:

* What did you expect to happen?