refactor: Use only one temporary buffer in CreateObfuscateKey

src/dbwrapper.cpp

@@ -220,10 +220,9 @@ const unsigned int CDBWrapper::OBFUSCATE_KEY_NUM_BYTES = 8;
  */
 std::vector<unsigned char> CDBWrapper::CreateObfuscateKey() const
 {
-    unsigned char buff[OBFUSCATE_KEY_NUM_BYTES];
-    GetRandBytes(buff, OBFUSCATE_KEY_NUM_BYTES);
-    return std::vector<unsigned char>(&buff[0], &buff[OBFUSCATE_KEY_NUM_BYTES]);
-
+    std::vector<uint8_t> ret(OBFUSCATE_KEY_NUM_BYTES);
+    GetRandBytes(ret.data(), OBFUSCATE_KEY_NUM_BYTES);
+    return ret;
 }
 
 bool CDBWrapper::IsEmpty()