Small fix/improvement

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

@@ -423,7 +423,7 @@ public class ConnectionHelper {
     }
 
     static boolean airplaneMode(Context context) {
-        return Settings.System.getInt(context.getContentResolver(),
+        return Settings.Global.getInt(context.getContentResolver(),
                 Settings.Global.AIRPLANE_MODE_ON, 0) != 0;
     }
 }

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

@@ -377,6 +377,9 @@ public class FragmentOptionsConnection extends FragmentBase implements SharedPre
                     if (lp != null)
                         sb.append(lp).append("\r\n\r\n");
                 }
+
+                sb.append("Airplane mode=")
+                        .append(ConnectionHelper.airplaneMode(context)).append("\r\n\r\n");
             } catch (Throwable ex) {
                 Log.e(ex);
             }