I have the same problem today with the latest update!
--- Log file: C:\Program Files\Eagle Dynamics\DCS World\autoupdate_log.txt
=== Log opened UTC 2017-12-16 00:25:15
INFO : DCS_Updater/2.6.22.24 (Windows NT 10.0.15063; Win64; es-MX)
INFO : cmdline: "C:\Program Files\Eagle Dynamics\DCS World\bin\DCS_updater.exe" --apply repair
STATUS: Initializing...
INFO : basedir: C:\Program Files\Eagle Dynamics\DCS World
INFO : DCS/1.5.7.11762.396 (x86_64; EN; WORLD,KA-50,CA,FC3,KA-50_video_EN,A-10C,SU27-ULTIMATE_campaign,MIG-21BIS,MI-8MTV2)
INFO : branch:
STATUS: Connecting to update servers...
INFO : Got reply from http://www.digitalcombatsimulator.com
ERROR: Conection to server 'srv4update.digitalcombatsimulator.com' failed: SSL peer certificate or SSH remote key was not OK
ERROR: srv4update.digitalcombatsimulator.com replied HTTP -1
ERROR: SSL peer certificate or SSH remote key was not OK
=== Log closed.