Remove old TODO as we don't support multiple instances for now.

As there aren't any more generic meta data containers inside BKey,
there's no real way to distinguish different instances with the same
identifiers. This may be added later, for example the same index system
as used in BMessage could apply.

headers/os/app/KeyStore.h

@@ -14,8 +14,6 @@ public:
 								BKeyStore();
 	virtual						~BKeyStore();
 
-// TODO: -> GetNextPassword() - there can always be more than one key
-// with the same identifier/secondaryIdentifier (ie. different username)
 			status_t			GetKey(BKeyType type, const char* identifier,
 									BKey& key);
 			status_t			GetKey(BKeyType type, const char* identifier,