[Monit] Fix a typo.

Signed-off-by: Yong Zhao <[email protected]>

files/image_config/monit/process_checker

@@ -33,7 +33,7 @@ def check_process_existence(container_name, process_cmdline):
                     break
 
             if not is_running:
-                # If this script is run by Monit, then the following output will be appneded to
+                # If this script is run by Monit, then the following output will be appended to
                 # Monit's syslog message.
                 print("'{}' is not running.".format(process_cmdline))
                 sys.exit(1)