fix NPE for incoming failed messages

Fixes #2807
// FREEBIE

src/org/thoughtcrime/securesms/ConversationItem.java

@@ -313,9 +313,11 @@ public class ConversationItem extends LinearLayout {
 
   private void setFailedStatusIcons() {
     dateText.setText(R.string.ConversationItem_error_not_delivered);
+    if (indicatorText != null) {
       indicatorText.setText(R.string.ConversationItem_click_for_details);
       indicatorText.setVisibility(View.VISIBLE);
     }
+  }
 
   private void setFallbackStatusIcons() {
     pendingIndicator.setVisibility(View.VISIBLE);