Make FcPatternDuplicate copy the binding instead of always using Strong.

I noticed that Qt always uses a different font than fc-match advertises.
Debugging the issue, I found that a call that looks pretty innocent is
changing all weak bindings to strong bindings and as such changes the
semantic of the match: FcPatternDuplicate.

src/fcpat.c

@@ -925,10 +925,14 @@ FcPatternDuplicate (const FcPattern *orig)
     for (i = 0; i < orig->num; i++)
     {
 	for (l = FcPatternEltValues(e + i); l; l = FcValueListNext(l))
-	    if (!FcPatternObjectAdd (new, e[i].object,
+	{
+	    if (!FcPatternObjectAddWithBinding (new, e[i].object,
 						FcValueCanonicalize(&l->value),
+						l->binding,
 						FcTrue))
 		goto bail1;
+	    
+	}
     }
 
     return new;