Prevent removing attached images

app/src/main/java/eu/faircode/email/FragmentCompose.java

@@ -4285,8 +4285,8 @@ public class FragmentCompose extends FragmentBase {
                             }
 
                             for (EntityAttachment attachment : new ArrayList<>(attachments))
-                                if (attachment.isInline() && attachment.isImage() &&
+                                if (!attachment.isAttachment() && attachment.isImage() &&
-                                        !cids.contains(attachment.cid)) {
+                                        attachment.cid != null && !cids.contains(attachment.cid)) {
                                     Log.i("Removing unused inline attachment cid=" + attachment.cid);
                                     db.attachment().deleteAttachment(attachment.id);
                                 }