Gap under cill of sliding patio doors

[richie9648!]

Hi

Suggestions of solving this gap between patio door and brick work. There are no problems and water ingress but is a bit untidy

 

[freddiemercurystwin]

Got a pic from further away?

 

[RrogerD]

I thought that the gap was supposed to be there to permit drainage of water getting into the door frame.