Test maintenancetool update in old Linux distro

In old Linux distros (glibc version older than 2.28), maintenance tool version 4.7.0 and installer version 4.7.0 won't start.
When running 4.6.x installer in these old distros (for example Ubuntu 18), the maintenancetool is not updated to version 4.7.0
Test cases:
1. Run installer version 4.6.x and install something (for example cmake)

• check that qt.tools.maintenance is not found from components.xml -file
• check running 'maintenancetool --version' that 4.6.x version is printed

2. Run maintenancetool update

• update anything, does not matter what
• check that the maintenancetool is not updated, but the selected components are

3. Run maintenancetool install

• install anything, does not matter what
• check that the maintenancetool is not installed, but the selected components are