Fixed bug in header, wherein all images were assigned to the first

header in a section. This resulted in a corrupt DOCX

Author: Bas-Jan 't Jong

src/PhpWord/Element/AbstractContainer.php

@@ -249,7 +249,6 @@ public function addImage($src, $style = null, $isWatermark = false)
         $rId = Media::addElement($elementDocPart, 'image', $src, $image);
         $image->setRelationId($rId);
         $this->addElement($image);
-
         return $image;
     }
 
@@ -413,7 +412,7 @@ private function checkElementDocPart()
         $docPart = $isCellTextrun ? $this->getDocPart() : $this->container;
         $docPartId = $isCellTextrun ? $this->getDocPartId() : $this->sectionId;
         $inHeaderFooter = ($docPart == 'header' || $docPart == 'footer');
-
+        $docPartId = $inHeaderFooter ? $this->getDocPartId() : $docPartId;
         return $inHeaderFooter ? $docPart . $docPartId : $docPart;
     }