Retry immedialtly the download in the type of file differ.

[LucsT]

During saveBills, saveFiles function, we download files.
If files are in the mime/type expect. It could interesting to add one or two retry to the download.
This test is already done, but only on next run of the connector.

A nice example is bipandgo when an error occur downloading the pdf, they served a weird page. We ended with a html in a .pdf extension.
As the error is erratic, a simple retry immediatly should resolve or limit the problem.