fix nullable variables

core/model/src/main/kotlin/dev/meloda/fast/model/api/data/VkChannelMessageData.kt

@@ -11,7 +11,7 @@ data class VkChannelMessageData(
     @Json(name = "author_id") val authorId: Long,
     @Json(name = "channel_info") val channelInfo: ChannelInfo,
     @Json(name = "channel_type") val channelType: String,
-    @Json(name = "guid") val guid: String,
+    @Json(name = "guid") val guid: String?,
     @Json(name = "text") val text: String?,
     @Json(name = "time") val time: Long,
     @Json(name = "attachments") val attachments: List<VkAttachmentItemData> = emptyList(),

core/model/src/main/kotlin/dev/meloda/fast/model/api/domain/VkChannelMessage.kt

@@ -8,7 +8,7 @@ data class VkChannelMessage(
     val authorId: Long,
     val channelInfo: ChannelInfo,
     val channelType: String,
-    val guid: String,
+    val guid: String?,
     val text: String?,
     val time: Long,
     val attachments: List<VkAttachment>?,