ci: Adjust more 'spawn' settings in test_confserver

tools/kconfig_new/test/test_confserver.py

@@ -51,9 +51,7 @@ def main():
 
         cmdline = "../confserver.py --kconfig Kconfig --config %s" % temp_sdkconfig_path
         print("Running: %s" % cmdline)
-        p = pexpect.spawn(cmdline, timeout=2)
-        p.logfile = args.logfile
-        p.setecho(False)
+        p = pexpect.spawn(cmdline, timeout=30, logfile=args.logfile, echo=False, use_poll=True, maxread=1)
 
         p.expect("Server running.+\r\n")
         initial = expect_json(p)