Prevent NPE

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

@@ -870,9 +870,11 @@ public class MessageHelper {
                 String email = ((InternetAddress) from).getAddress();
                 String user = UriHelper.getEmailUser(email);
                 String domain = UriHelper.getEmailDomain(email);
-                Pair<String, String> extra = getExtra(email, message.extra);
+                if (message.extra != null) {
-                if (extra.second != null)
+                    Pair<String, String> extra = getExtra(email, message.extra);
-                    email = extra.second;
+                    if (extra.second != null)
+                        email = extra.second;
+                }
                 address = address
                         .replace("$from$", email)
                         .replace("$user$", user)