Makefile: add read permissions on all firmwares before uploading

Reviewed-by: wazo-community-zuul[bot]

Add default value for proxy port to Gigaset N510 avoid it crashing

Note: has not yet been tested on a phone

Reviewed-by: Alexandre Fournier

[WP-739] fanvil: add support for top function keys

Reviewed-by: Jesse Sopel

[WAZO-3444] add missing server URL in common files generation

Reviewed-by: Pascal Cadotte Michaud

cisco-sip: fix server url in model templates

Reviewed-by: wazo-community-zuul[bot]

cisco-sip: fix missing server_url in common.py

Reviewed-by: wazo-community-zuul[bot]

WAZO-1760: provd behind reverse proxy

Reviewed-by: Pascal Cadotte Michaud <None>

fix for alcatel NOE

Reviewed-by: Alexandre Fournier <None>
Reviewed-by: Franck M <contact@voipservices.fr>