Make sure potential big files are checked with Range header

[erwanlr]

It's already done for log files, just have to do it for files which can go big (such as sql dumps etc)

If the server doesn't support the Range header, well ... the maxfilesize of Typhoeus won't be of any use as we won't have the output returned :/

Files I can think of:

• https://github.com/wpscanteam/wpscan/blob/master/app/finders/db_exports/known_locations.rb
• https://github.com/wpscanteam/wpscan/blob/master/app/finders/interesting_findings/tmm_db_migrate.rb (here we can use the maxfilesize as we don't check the body head will be even better)
• https://github.com/wpscanteam/wpscan/blob/master/app/finders/interesting_findings/upload_sql_dump.rb