SVN: only allow redirects to HTTPS

SVN: only allow redirects to HTTPS

"SVN follows HTTP 301 redirects to svn+ssh:// URLs. As a result, an
innocent looking HTTP URL can be used to trigger a Command Execution with a
301 redirect."
https://blog.recurity-labs.com/2017-08-10/scm-vulns.html#third-round-svn-and-mercurial

I scanned fdroiddata and found no suspicious redirects.  Here's how:

grep -A1 '^Repo *Type: *git-svn' *.txt *.yml| sed -n 's,.*Repo:\(.*\),\1,p' > /tmp/urls.txt

import requests
with open('/tmp/urls.txt') as fp:
    for line in fp:
        try:
            r = requests.head(line.strip())
            print(r.status_code, line)
        except requests.exceptions.SSLError:
            print('SSLError', line)