Update CODEOWNERS

Signed-off-by: Sergey Fedorov <sergey.fedorov@neclab.eu>

Author: Sergey Fedorov

.github/CODEOWNERS

@@ -1,8 +1,8 @@
 * @nhoriguchi @ynamiki
 
-/api/ @sergefdrv @nhoriguchi
-/client/ @sergefdrv @nhoriguchi
-/core/ @sergefdrv @nhoriguchi
-/messages/ @sergefdrv @nhoriguchi
-/sample/ @sergefdrv @nhoriguchi
-/usig/ @sergefdrv @nhoriguchi
+/api/ @luthlee @nhoriguchi
+/client/ @luthlee @nhoriguchi
+/core/ @luthlee @nhoriguchi
+/messages/ @luthlee @nhoriguchi
+/sample/ @luthlee @nhoriguchi
+/usig/ @luthlee @nhoriguchi