message: camera: fix exception when instantiating string
diff: @@ -242,7 +242,7 @@ public:
  uint16_t resolution_v_pix = 0u; /**< @brief Resolution verticle in pixels. */
  uint32_t bit_rate_b_s = 0u; /**< @brief Bit rate in bits per second. */
  uint16_t rotation_deg = 0u; /**< @brief Video image rotation clockwise (0-359 degrees) */
  - std::string uri = nullptr; /**< @brief Video stream URI */
  + std::string uri {}; /**< @brief Video stream URI */
  void set_highest()
  {
  