remove MessageAttachment model.

app/src/main/java/chat/rocket/android/model/ddp/Message.java

@@ -23,7 +23,7 @@ public class Message extends RealmObject {
   private String msg;
   private User u;
   private boolean groupable;
-  private RealmList<MessageAttachment> attachments;
+  private String attachments; //JSONArray.
   private RealmList<MessageUrl> urls;
 
   public String get_id() {
@@ -90,11 +90,11 @@ public class Message extends RealmObject {
     this.groupable = groupable;
   }
 
-  public RealmList<MessageAttachment> getAttachments() {
+  public String getAttachments() {
     return attachments;
   }
 
-  public void setAttachments(RealmList<MessageAttachment> attachments) {
+  public void setAttachments(String attachments) {
     this.attachments = attachments;
   }
 

app/src/main/java/chat/rocket/android/model/ddp/MessageAttachment.java

-package chat.rocket.android.model.ddp;
-
-import io.realm.RealmObject;
-
-/**
- * Attachment.
- */
-@SuppressWarnings({"PMD.ShortClassName", "PMD.ShortVariable",
-    "PMD.MethodNamingConventions", "PMD.VariableNamingConventions"})
-public class MessageAttachment extends RealmObject {
-  private String title;
-  private String title_url;
-  private String image_url;
-  private String image_type;
-  private String image_size;
-}