ingest_tileset probably does not work with ftp

[mccalluc]

higlass-server/tilesets/management/commands/ingest_tileset.py

Line 34 in 5a189e2

if filename[:8] == 'ftp://':

This will never evaluate to True: The character count is wrong.
startswith would be better... or the three if-thens could be replaced with a single regex.

[mildewey]

Looks like a pretty clear case of copy-paste error. I've fixed it in PR 100, but I don't have an ftp server handy to test against. @mccalluc do you know where we could get one? If we can find a stable one, I'd be happy to amend a test for this.