more incredibly minor mailsession dependancy cleanup (no reviewer)

mailnews/base/util/nsMsgFolder.cpp

@@ -37,6 +37,7 @@
 #include "nsXPIDLString.h"
 #include "nsCOMPtr.h"
 #include "nsIMsgMailSession.h"
+#include "nsIMsgAccountManager.h"
 #include "nsMsgBaseCID.h"
 #include "nsIAllocator.h"
 #include "nsIURL.h"

mailnews/base/util/nsMsgMailNewsUrl.cpp

@@ -24,6 +24,7 @@
 #include "nsMsgMailNewsUrl.h"
 #include "nsMsgBaseCID.h"
 #include "nsIMsgMailSession.h"
+#include "nsIMsgAccountManager.h"
 #include "nsXPIDLString.h"
 #include "nsIDocumentLoader.h"
 #include "nsILoadGroup.h"