Initialize paragraph descent in wxRichTextParagraph::Layout().

This variable was used as the initial value for the descent but was never
initialized, so the descent computation could be completely wrong.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@66099 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/richtext/richtextbuffer.cpp

@@ -3607,7 +3607,7 @@ bool wxRichTextParagraph::Layout(wxDC& dc, const wxRect& rect, int style)
     wxArrayInt partialExtents;
 
     wxSize paraSize;
-    int paraDescent;
+    int paraDescent = 0;
 
     // This calculates the partial text extents
     GetRangeSize(GetRange(), paraSize, paraDescent, dc, wxRICHTEXT_UNFORMATTED|wxRICHTEXT_CACHE_SIZE, wxPoint(0,0), & partialExtents);