GitLab

Do not use MainDbChatMessageKey
add resetStorageId in main db event key and use it instead of replacing main db event key  with an empty object

Thanks Simon

Fix bad dynamic cast.
Relax times in testers.

Add linphone_event_remove_custom_header and C++ implementation
Remote unused ChatMessage customHeader code

Clean code duplicated by merge accident.

Make liblinphone_tester able to use a dns server from a flexisip-tester infrastructure, in order to retrieve all the hosts. It allows to use SRV queries.