podcast: podcast download should not fail when local file is empty
This MR fixes 3 issues.
- Allow podcast download to be initiated even if
local_size = 0
anddata->download_size = 0
, in case if we are not able to ascertaindownload_size
value from GIO. We allow the download to proceed. - Prevent podcast download from failing with
File exists
error, in case of empty local file, due tog_file_create()
usage. - Do not print "podcast partly downloaded (0 of 1231231)" in debug message.