Fix calculation of internal leading

Stupid me, I totally messed this up! God only knows how many non-bugs
people had to fix because of this typo.

Has the side effect of fixing fdo#64972 (among many others of course,
but this is the only one still open).

Change-Id: I9d8fdb6d37d4af9b0ac973902e469e0bd3a2408a

vcl/generic/glyphs/gcach_ftyp.cxx

@@ -989,7 +989,7 @@ void ServerFont::FetchFontMetric( ImplFontMetricData& rTo, long& rFactor ) const
         }
     }
 
-    rTo.mnIntLeading = (rTo.mnAscent + rTo.mnDescent) - ((maFaceFT->units_per_EM + 32) >> 6);
+    rTo.mnIntLeading = rTo.mnAscent + rTo.mnDescent - (maFaceFT->units_per_EM * fScale + 0.5);
 
     if( pOS2 && (pOS2->version != 0xFFFF) )
     {