[ipcamera] Fix connection checks with ONVIF cameras with no snapshots#15119

lolodomo merged 5 commits intoopenhab:mainopenhab/openhab-addons:mainfrom

tb4jc:14910-fix-stop-poll-image-connection-handlingtb4jc/openhab-addons:14910-fix-stop-poll-image-connection-handlingCopy head branch name to clipboard