ofz: handle empty paragraphs case

Change-Id: I4c928f55881c1f9147eec1018381b3d3064c58ee
Reviewed-on: https://gerrit.libreoffice.org/45592Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

oox/source/drawingml/textbody.cxx

@@ -95,6 +95,9 @@ void TextBody::ApplyStyleEmpty(
 {
     assert(isEmpty());
 
+    if (maParagraphs.empty())
+        return;
+
     // Apply character properties
     TextListStyle aCombinedTextStyle;
     aCombinedTextStyle.apply( *pMasterTextListStylePtr );