Include nsIPrincipal.h just to be safe. (The unix tree turned red, but I don't know if it was a midcheckin problem

or if it really needs this).

mailnews/base/util/nsMsgProtocol.h

@@ -26,6 +26,7 @@
 #include "nsIChannel.h"
 #include "nsIURL.h"
 #include "nsILoadGroup.h"
+#include "nsIPrincipal.h"
 #include "nsCOMPtr.h"
 
 // This is a helper class used to encapsulate code shared between all of the