It seems to be a connection timeout. Did you try this API in a tool like postman? How is the reaction time?
It seemed there is a connection time out. Are you sure you are using the right address and port?
Indeed a connection timeout. See the logline:
Caused by: com.mendix.systemwideinterfaces.MendixRuntimeException: java.security.PrivilegedActionException: org.apache.http.conn.HttpHostConnectException: Connect to en.wikipedia.org:443 [en.wikipedia.org/91.198.174.192] failed: Connection timed out: connect
at com.mendix.integration.util.PrivilegedUtil$.withPrivileged(PrivilegedUtil.scala:15)
Port 443 is a SSL port, so a secured port. Do you have authentication set up correctly?
It looks like it tries to setup a HTTP (port 80) connection to a HTTPS (port 443) host, did you exactly put https://en.wikipedia.org as URL in the REST GET activity?