changed: in Crypto::Crypt()

MSVC compiler in debug mode reports accessing to vector[0] element (assertion)
         when the vector was empty
         (we took only a pointer without dereferencing)
         now we are using a dummy char object in such a case


git-svn-id: svn://ttmath.org/publicrep/tito/trunk@398 e52654a7-88a9-db11-a3e9-0013d4bc506e

src/crypto.h

@@ -51,6 +51,7 @@ class Crypto
 {
 public:
 
+	Crypto();
 
 	/*
 		setting AES256 key
@@ -106,6 +107,9 @@ private:
 	std::string base64_str;
 	std::string aes_str;
 
+	// a dummy character used when an input string is empty
+	unsigned char dummy_char;
+
 	void Clear();