Made user nullable in participant

models/participant.go

@@ -24,7 +24,7 @@ type DBParticipant struct {
 
 	Sessions []DBSession `gorm:"foreignKey:ParticipantId;references:Id"`
 	Calls    []DBCall    `gorm:"foreignKey:ParticipantId;references:Id"`
-	User     GCUser      `gorm:"foreignKey:UserId;references:Id`
+	User     *GCUser     `gorm:"foreignKey:UserId;references:Id`
 }
 
 func (DBParticipant) TableName() string {