backend url fix

dta/settings.php

@@ -31,4 +31,4 @@ $settings->add(new admin_setting_configcheckbox("assignsubmission_dta/default",
 
 $settings->add(new admin_setting_configtext("assignsubmission_dta/backendHost",
     new lang_string("backendHost", "assignsubmission_dta"),
-    new lang_string("backendHost_help", "assignsubmission_dta"), "http://dtabackend:8080"));
+    new lang_string("backendHost_help", "assignsubmission_dta"), "http://backend:8080"));