Refresh system config after writing yast_config to the system (bsc#1162987)

[teclator]

Problem

Network system configuration is cached by YaST the first time it is read, and then it is not refreshed when it is written, thus, some config is not written as it does not see differences between the yast_config and the system_config.

In this case, before setting the dhcp configuration, the DHCLIENT_SET_HOSTNAME is no.

YaST enables it when setting the DHCP configuration based on the control file default as implemented in #564

Then, the option is set to yes in yast_config, it is written to the config file, but it is still cached as no in the system_config. Which means, that if we set it to no in the GUI later (yast_config), it will not be modified because it is the same in yast_config and system_config.

• https://trello.com/c/OE476t1s/1728-sles15-sp2-p2-1162987-build-1362-openqa-test-fails-in-hostnameinst-dhclientsethostname-is-not-set-to-no-by-yast-after-user-chang

Solution

• Replace the cached system network config by the written one after writing.

Tests

• tested manually

[coveralls]

Coverage decreased (-0.006%) to 70.369% when pulling 17fe3b2 on refresh_system_config into bbefa54 on master.

[yast-bot]

✔️ Public Jenkins job #142 successfully finished
✔️ Created OBS submit request #789096

[yast-bot]

✔️ Internal Jenkins job #79 successfully finished
✔️ Created IBS submit request #214868