template/detect: allow empty buffers

rust/src/applayertemplate/detect.rs

@@ -48,19 +48,15 @@ unsafe extern "C" fn template_buffer_get_data(
     let tx = cast_pointer!(tx, TemplateTransaction);
     if flags & Direction::ToClient as u8 != 0 {
         if let Some(ref response) = tx.response {
-            if !response.is_empty() {
             *len = response.len() as u32;
             *buf = response.as_ptr();
             return true;
         }
-        }
     } else if let Some(ref request) = tx.request {
-        if !request.is_empty() {
         *len = request.len() as u32;
         *buf = request.as_ptr();
         return true;
     }
-    }
     return false;
 }