Fix missing default values for Contest relation

db/src/entity/Contest.ts

@@ -23,13 +23,13 @@ export class Contest {
     @Column()
     voteReaction: string;
 
-    @Column()
+    @Column({ default: 1 })
     maxWinners: number;
 
-    @Column()
+    @Column({ default: true })
     uniqueWinners: boolean;
 
-    @Column()
+    @Column({ default: false })
     active: boolean;
 
     @OneToMany(type => ContestEntry, entry => entry.contest)