fix crash when loading timelines

app/src/main/java/com/keylesspalace/tusky/entity/Status.kt

@@ -31,8 +31,8 @@ data class Status(
         val emojis: List<Emoji>,
         @SerializedName("reblogs_count") val reblogsCount: Int,
         @SerializedName("favourites_count") val favouritesCount: Int,
-        var reblogged: Boolean?,
+        var reblogged: Boolean = false,
-        var favourited: Boolean?,
+        var favourited: Boolean = false,
         var sensitive: Boolean,
         @SerializedName("spoiler_text") val spoilerText: String,
         val visibility: Visibility,