* Content-Type is optional
mime.ParseMimeType returns and "no media type" error if the passed
string is empty.
Given that the Content-Type header is optional we shouldn't return an error
in that case, so we're fixing that allowing the users to call the webhook
without passing that header
* Include webhook id in the error message
Given that the number of webhooks could be big the user could
need the id to check which one of the multiple webhooks are failing
so include the id aids in that part
* Consistent license message for all the go files
* Fixing the last set of unconsistencies with the license headers
* Addressing PR review comments
* Fixing busy.go and busy_test.go license header
* MM 10658 Change config fields to pointers (#8898)
* Change fields of config structs to pointers and set defaults
MM-10658 https://github.com/mattermost/mattermost-server/issues/8841
* Fix tests that go broken during switching config structs to pointers
MM-10658 https://github.com/mattermost/mattermost-server/issues/8841
* Apply changes of current master while switching config structs to pointers
MM-10658 https://github.com/mattermost/mattermost-server/issues/8841
* Fix new config pointer uses
* Fix app tests
* Fix mail test
* remove debugging statement
* fix TestUpdateConfig
* assign config consistently
* initialize AmazonS3Region in TestS3TestConnection
* initialize fields for TestEmailTest
* fix TestCheckMandatoryS3Fields
* Refactor context out of API packages
* Update function names per feedback
* Move webhook handlers to web and fix web tests
* Move more webhook tests out of api package
* Fix static handler
