small adaptation to search string in check_for_warnings.py
search for "warning" instead of "warning:" to make the script work on windows as well
WARNING! Gitlab maintenance operation scheduled for Monday, 20 April between 12:00 and 14:00 (CET). During this time window, short service interruptions (less than 5 minutes) may occur. Thank you in advance for your understanding.
search for "warning" instead of "warning:" to make the script work on windows as well