Do not crash if RECIPIENT_EXTRA is null.

app/src/main/java/org/thoughtcrime/securesms/conversation/ConversationActivity.java

@@ -434,9 +434,7 @@ public class ConversationActivity extends PassphraseRequiredActivity
 
   @Override
   protected void onCreate(Bundle state, boolean ready) {
-    RecipientId recipientId = getRecipientId(getIntent());
-
-    if (recipientId == null) {
+    if (getIntent().getStringExtra(RECIPIENT_EXTRA) == null) {
       Log.w(TAG, "[onCreate] Missing recipientId!");
       // TODO [greyson] Navigation
       startActivity(new Intent(this, MainActivity.class));
@@ -444,6 +442,8 @@ public class ConversationActivity extends PassphraseRequiredActivity
       return;
     }
 
+    RecipientId recipientId = getRecipientId(getIntent());
+
     reportShortcutLaunch(recipientId);
     setContentView(R.layout.conversation_activity);