Be more explicit about package_control_channel.
Be more explicit about package_control_channel.

simonzack/SublimeLinter3,zenlambda/SublimeLinter3,ikappas/SublimeLinter3,ikappas/SublimeLinter3,smanolloff/SublimeLinter3,SublimeLinter/SublimeLinter3,smanolloff/SublimeLinter3,jasonrhaas/SublimeLinter3,zenlambda/SublimeLinter3,SublimeLinter/SublimeLinter3,jasonrhaas/SublimeLinter3,simonzack/SublimeLinter3