that special case was a really stupid idea, tdf#91685

The default value is context depending and not 0. So always export the
rotation value.

Change-Id: I36162459757c58846f3ecea7dcbcb58b6ef3d1f6

oox/source/export/chartexport.cxx

@@ -1110,7 +1110,7 @@ void ChartExport::exportTitle( Reference< XShape > xShape )
 
     pFS->singleElement( FSNS( XML_a, XML_bodyPr ),
             XML_vert, sWritingMode,
-            XML_rot, nRotation == 0 ? NULL : calcRotationValue(nRotation).getStr(),
+            XML_rot, calcRotationValue(nRotation).getStr(),
             FSEND );
     // TODO: lstStyle
     pFS->singleElement( FSNS( XML_a, XML_lstStyle ),