allow range request for every content type, move lock only when metad…

[paolafrancesca]

…ata has to be updated

[paolafrancesca]

related to #409

see https://github.com/dutchcoders/transfer.sh/issues/490#issuecomment-1179545800 and https://github.com/dutchcoders/transfer.sh/issues/490#issuecomment-1179654566

@stefanbenten can you take a look when you have time?

this is to add the support on transfer.sh service, hosted instances like https://transfer.sh might require tuninque eventual proxy on top of the service

[stefanbenten]

Let me see, if i can push this PR sometime today..

[paolafrancesca]

closed in favor of #527

we still should keep https://github.com/dutchcoders/transfer.sh/pull/495/files#diff-961509ed3ff668f3172148150903514fb3394d6ff090d6db78d986875b13689fR705-R706, for donwloaders that send multiple concurrent range request