modifs.mineures sans commentaires

src/spout/SpoutBuilder.php

@@ -355,6 +355,7 @@ class SpoutBuilder extends AbstractBuilder {
         unset($rowStyle[$method]);
         if ($value !== null) $rowParams[$method] = $value;
       }
+      if ($rowStyle === []) $rowStyle = null;
     }
     $sheetParams = $this->sheetParams;
     $headerStyle = $sheetParams["header_style"] ?? null;