[addons] fix addon settings not showing up (lsep, sep)
CPODocument::LoadFile: do not log error if file does not exist
Merge pull request #5028 from Karlson2k/fix_CPODocument_01

Fix for errors in log after fa9f662af783033c21f5f40f07b563fa843ae799
Merge pull request #5025 from jmarshallnz/id_empty

[addons] fix addon settings not showing up (lsep, sep)
[url] use IsProtocol in place of GetProtocol
[fileitem] drop GetAsUrl() as GetURL() does the same thing