Use ngx_log_error! macro and fix formatting

- Switched from ngx_log_error_core() to ngx_log_error! macro
- Changed error_log level from debug to info (cleaner output)
- Formatting cleanup across all modules (cargo fmt)
- Removed trailing newlines and fixed indentation

Logging now properly uses nginx's macro system for better
integration with nginx's log handling.

src/config.rs

@@ -130,4 +130,3 @@ mod tests {
         assert_eq!(config.global_templates_dir, "templates/global");
     }
 }
-