TEdit NumbersOnly does not work under Linux Mint & Ubuntu

Original Reporter info from Mantis: uomosaturno

• Reporter name: Markus

Description:

Under Linux Mint and Ubuntu the numbers Only property of the TEdit component doesn't work, while it does with Win7.
It is possible to enter e.g. characters.

Steps to reproduce:

- drop Tedit on a form
- set NumbersOnly to true
- compile & run
- enter a character

Mantis conversion info:

• Mantis ID: 33704
• OS: Linux Mint
• OS Build: 18.3
• Build: 2018-03-17
• Platform: X86
• Version: 1.8.2
• Fixed in version: 2.0
• Fixed in revision: r59981 (#c42877a3)
• Target version: 2.0