[BUG] Upload/Downloadspeed can only be changed by holding the arrows in the field

[Termuellinator]

Describe the bug
On the "Data" Page, the max networkspeed can't be set by typing in numbers - you have to use the arrows which is quite time consuming with a broadband connection

I think it would be nice to not have a fixed graph range for network speed but adapting to the currenct throughput.

besides that: thanks for taking over the abandoned project :)

Versions (please complete the following information):

• Version : 2.1.2
• KDE Plasma Version : 5.21.5
• KDE Frameworks Version : 5.82.0
• Qt Version : 5.15.2
• Kernel Version : 5.12.9-1-MANJARO
• OS Type : 64bit
• Graphics Platform : X11