Only drop channel handlers if throwing an exception in case of declaration/get failure#731

milyin merged 1 commit intoeclipse-zenoh:maineclipse-zenoh/zenoh-cpp:mainfrom

DenisBiryukov91:fix-handler-drop-in-case-of-errorDenisBiryukov91/zenoh-cpp:fix-handler-drop-in-case-of-errorCopy head branch name to clipboard