[MCL-5475] Time is off by two hours when using custom log config and not enabling XML output

The bug

The time logged by the launcher is off by two hours while it uses any custom log config:

16:29:29	launcher	Preparing to launch minecraft client for 1.12.2
16:29:29	launcher	Checking installations.
16:29:29	launcher	Minecraft client 1.12.2 is ready to start.
16:29:29	launcher	Starting!
16:29:29	launcher	Using custom game log configuration C:\Users\bemoty\Desktop\test.xml (outputs plaintext)
18:29:30	game	[Fatal Error] test.xml:2:35: The string "--" is not permitted within comments.
18:29:30	game	ERROR StatusLogger Error parsing C:\Users\bemoty\Desktop\test.xml

How to reproduce

Enable Advanced settings in the launcher profiles tab
Enable Open output log when the game starts in the settings tab (launcher settings)
Edit a profile and set the attached file test.xml as the custom log config

Note: Happened with a PC in UTC+1 but setting the time zone to UTC or UTC+2 still caused an two hour offset.