Fix for crash when opening group conversation

Fixes #6464
// FREEBIE

src/org/thoughtcrime/securesms/ConversationItem.java

@@ -27,7 +27,6 @@ import android.net.Uri;
 import android.os.AsyncTask;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
-import android.support.v7.app.ActionBar;
 import android.support.v7.app.AlertDialog;
 import android.text.TextUtils;
 import android.text.util.Linkify;
@@ -339,7 +338,7 @@ public class ConversationItem extends LinearLayout
       documentViewStub.get().setDownloadClickListener(downloadClickListener);
       documentViewStub.get().setOnLongClickListener(passthroughClickListener);
 
-      bodyText.setLayoutParams(new ActionBar.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
+      bodyText.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
     } else if (hasThumbnail(messageRecord)) {
       mediaThumbnailStub.get().setVisibility(View.VISIBLE);
       if (audioViewStub.resolved())    audioViewStub.get().setVisibility(View.GONE);

src/org/thoughtcrime/securesms/util/MediaUtil.java

@@ -83,7 +83,7 @@ public class MediaUtil {
       slide = new AudioSlide(context, attachment);
     } else if (isMms(attachment.getContentType())) {
       slide = new MmsSlide(context, attachment);
-    } else {
+    } else if (attachment.getContentType() != null) {
       slide = new DocumentSlide(context, attachment);
     }