Update WorksheetManager.php

fix the space

src/Spout/Writer/XLSX/Manager/WorksheetManager.php

@@ -272,7 +272,7 @@ EOD;
 
         \fwrite($worksheetFilePointer, '</sheetData>');
         // do sth to merging cells
-                $mergeRanges = $worksheet->getExternalSheet()->getMergeRanges();
+        $mergeRanges = $worksheet->getExternalSheet()->getMergeRanges();
         if(!empty($mergeRanges)) {
             $startLine = '<mergeCells count="1">';
             $rangeLine = '';