update realm migration for FilterCondition

app/src/main/java/net/pokeranalytics/android/model/migrations/PokerAnalyticsMigration.kt

@@ -61,12 +61,12 @@ class PokerAnalyticsMigration : RealmMigration {
                 it.removeField("blindValues")
                 it.removeField("numericValues")
 
-                it.addField("operator", Integer::class.java).setNullable("operator", true)
-                it.addField("intValue", Integer::class.java).setNullable("intValue", true)
-                it.addRealmListField("intValues", Integer::class.java).setNullable("intValues", true)
-                it.addField("doubleValue", Double::class.java).setNullable("doubleValue", true)
-                it.addRealmListField("doubleValues", Double::class.java).setNullable("doubleValues", true)
-                it.addField("stringValue", String::class.java).setNullable("stringValue", true)
+                it.addField("operator", Integer::class.java)
+                it.addField("intValue", Integer::class.java)
+                it.addRealmListField("intValues", Integer::class.java)
+                it.addField("doubleValue", Double::class.java)
+                it.addRealmListField("doubleValues", Double::class.java)
+                it.addField("stringValue", String::class.java)
             }
 
 			schema.get("ComputableResult")?.let {