fix: Fix usage error in /time command

When targeting a specific preference (`/time console off`)
the loop would continue to iterate through the remaining
categories after finding and applying the setting.

Because subsequent items would not match, it always resulted in
"invalid usage" printed as well after the success message.

src/command/cmd_funcs.c

@@ -5290,6 +5290,9 @@ cmd_time(ProfWin* window, const char* const command, gchar** args)
             cons_bad_cmd_usage(command);
             return TRUE;
         }
+        if (!set_all) {
+            break;
+        }
     }
     if (!set_all && n == ARRAY_SIZE(time_prefs)) {
         cons_bad_cmd_usage(command);