HGKeeper

Remove code for no-longer supported GTK

2021-10-09, Elliott Sales de Andrade

cdb6fdb07bc4

Remove code for no-longer supported GTK

We require GTK 3.24 now.

Testing Done:
Compile only.

Reviewed at https://reviews.imfreedom.org/r/1012/

# h1

## h2

### h3

#### h4

##### h5

###### h6

plain *emphasis* _emphasis_ ~~**strong**~~ __strong__ `code` plain

[Test link](https://pidgin.im)

`code`

```

code?

```