Default keep alive each 19 minutes

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

@@ -654,7 +654,7 @@ public class FragmentAccount extends FragmentEx {
                         if (TextUtils.isEmpty(password) && !insecure)
                             throw new Throwable(getContext().getString(R.string.title_no_password));
                         if (TextUtils.isEmpty(interval))
-                            interval = "9";
+                            interval = "19";
                         if (synchronize && drafts == null)
                             throw new Throwable(getContext().getString(R.string.title_no_drafts));
                         if (Color.TRANSPARENT == color)

app/src/main/res/layout/fragment_account.xml

@@ -352,7 +352,7 @@
             android:id="@+id/etInterval"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
-            android:hint="9"
+            android:hint="19"
             android:inputType="number"
             android:textAppearance="@style/TextAppearance.AppCompat.Medium"
             app:layout_constraintStart_toStartOf="parent"