DNS-over-TLS: Integration into web user interface

DNS-over-TLS: Integration into web user interface

- unbound init has been modified and do not uses 'update_forwarders' function if DoT has been detected.
- DoT works with forward.conf which includes also 'qname-minimization strict'.
- dnsovertls.cgi can be used to configure DoT connections but do also accepts other ports (e.g. 53).
- dot-indexCGI-check checks if and how the connections has been established and delivers the result
    to /var/ipfire/red/dot which will be used by index.cgi to deliver the status via color codes.
    color codes: red = server is off ; orange = DNSsec do not works but certificate is trustworthy and crypto works ; green = all is working.
- check_connections.sh is a shell script which checks all configured connections also with the above color codes.
- test_tls.sh is also a shell script which check also all configured connections but with the raw output of kdig.
- language file has only be adapted for english.

Signed-off-by: Erik Kapfer <ummeegge@ipfire.org>