Revert "utils.log: Write error messages to stderr"

This reverts commit 34aa8b7c. Writing
error messages to stderr would also include backtraces, something we
tried to avoid in the past.

Signed-off-by: Michael Hanselmann <hansmi@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

lib/utils/log.py

@@ -230,7 +230,7 @@ def SetupLogging(logfile, program, debug=0, stderr_logging=False,
     if debug:
       stderr_handler.setLevel(logging.NOTSET)
     else:
-      stderr_handler.setLevel(logging.ERROR)
+      stderr_handler.setLevel(logging.CRITICAL)
     root_logger.addHandler(stderr_handler)
 
   if syslog in (constants.SYSLOG_YES, constants.SYSLOG_ONLY):