Add eight missing headers...

How did you ever get this to compile if those
headers were removed from the precompiled header?

indra/newview/llfloaterurlentry.cpp

@@ -43,6 +43,7 @@
 #include "lluictrlfactory.h"
 #include "llwindow.h"
 #include "llviewerwindow.h"
+#include "llhttpclient.h"
 
 static LLFloaterURLEntry* sInstance = NULL;