It does not align to middle

**Describe the bug**
I set it to align to middle , but it does not it always aligns to the left side.

I**Expected behavior**
It should align to the middle

**Actual behavior**
aligns to the left side

**To Reproduce**
Set the horizantal alignment to middle in the main window settings

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Please run `$ guake --support`, and paste the results here. Don't put backticks (`` ` ``) around it! The output already contains Markdown formatting. And make sure you run the command **OUTSIDE** the Guake.

I am using it on Debian Bullseye

```
$ guake --support

Guake Version: 3.6.3

Vte Version: 0.58.2

Vte Runtime Version: 0.58.2

--------------------------------------------------
GTK+ Version: 3.24.13

GDK Backend: GdkX11.X11Display

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Desktop Session: fluxbox

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Display: :0.0

RGBA visual: True

Composited: False

* Monitor: 0 - SAM HDMI-1
* Geometry: 1920 x 1200 at 0, 0
* Size: 160 x 90 mm²
* Primary: True
* Refresh rate: 59.95 Hz
* Subpixel layout: unknown

```