fix(docker): preserve COMMIT_PENDING_HOURS default when env var is unset (#18604)

* docker: preserve commit pending default when env unset

* Apply suggestion from @nijel

Author: nijel

weblate/settings_docker.py

@@ -1443,7 +1443,7 @@
 
 DEFAULT_AUTOCLEAN_TM = get_env_bool("WEBLATE_AUTOCLEAN_TM", False)
 
-COMMIT_PENDING_HOURS = get_env_int("WEBLATE_COMMIT_PENDING_HOURS")
+COMMIT_PENDING_HOURS = get_env_int("WEBLATE_COMMIT_PENDING_HOURS", 24)
 
 CONTACT_FORM = get_env_str("WEBLATE_CONTACT_FORM", "reply-to", required=True)
 ADMINS_CONTACT = get_env_list("WEBLATE_ADMINS_CONTACT")