bug 1163070 - fix AtkHyperlinkImpl::getHyperlink after bug 1146518 r=surkov

bug 1146518 made getHyperlink() return null if either there was no proxy, or
there was no Accessible, which would always be true.  It should have tested
that neither was present.

accessible/atk/nsMaiInterfaceHyperlinkImpl.cpp

@@ -16,7 +16,7 @@ static AtkHyperlink*
 getHyperlinkCB(AtkHyperlinkImpl* aImpl)
 {
   AccessibleWrap* accWrap = GetAccessibleWrap(ATK_OBJECT(aImpl));
-  if (!accWrap || !GetProxy(ATK_OBJECT(aImpl)))
+  if (!accWrap && !GetProxy(ATK_OBJECT(aImpl)))
     return nullptr;
 
   if (accWrap)