profiles: fix application

moving to a DB meant empty slices in the Configuration & Policy structs
were being stored as null, and striking a nerve with Jellyfin.
Mediabrowser library change fixed that by de-nulling them itself, and a
new bool field called "Homescreen" is now used to decide if a profile
has a homescreen layout stored or not. This field is hopefully correctly
filled in during migration.

api-profiles.go

@@ -79,8 +79,9 @@ func (app *appContext) CreateProfile(gc *gin.Context) {
 		return
 	}
 	profile := Profile{
-		FromUser: user.Name,
-		Policy:   user.Policy,
+		FromUser:   user.Name,
+		Policy:     user.Policy,
+		Homescreen: req.Homescreen,
 	}
 	app.debug.Printf("Creating profile from user \"%s\"", user.Name)
 	if req.Homescreen {