Bug 462621 Make --disable-vista--sdk-requirements actually produce a working...

Bug 462621 Make --disable-vista--sdk-requirements actually produce a working build (regression from bug 459329) r=sdwilsh (NPOTDB)

toolkit/components/downloads/src/nsDownloadManager.cpp

@@ -2602,7 +2602,7 @@ nsDownload::OnStateChange(nsIWebProgress *aWebProgress,
       mPercentComplete = 100;
       mLastUpdate = PR_Now();
 
-#if defined(XP_WIN) && !defined(__MINGW32__) && !defined(WINCE)
+#ifdef DOWNLOAD_SCANNER
       PRBool scan = PR_TRUE;
       nsCOMPtr<nsIPrefBranch> prefs(do_GetService(NS_PREFSERVICE_CONTRACTID));
       if (prefs)