FormatException ishaAngle's value isn't define[Bug]

[k0T0z]

Describe the bug when selecting the following settings the app crashes: high latitude rule = twilight angle madhab = hanafi calculation method = umm al-qura

ishaAngle's value isn't define

When the exception was thrown, this was the stack:

0 CalculationParameters.nightPortions (package:adhan/src/calculation_parameters.dart:73:13)

1 new PrayerTimes._ (package:adhan/src/prayer_times.dart:169:49)

2 new PrayerTimes (package:adhan/src/prayer_times.dart:53:24)

To Reproduce Steps to reproduce the behavior:

1. Go to '...'
2. Click on '....'
3. Scroll down to '....'
4. See error

Expected behavior A clear and concise description of what you expected to happen.

Screenshots If applicable, add screenshots to help explain your problem.

Environment(please complete the following information):

• Dart Language Version: [e.g. Dart 2.1]
• Flutter Version: [if applicable, e.g. Flutter 1.9.1]
• Adhan-Dart Version: [e.g. 1.1.15, 2.0.0-nullsafety.1]

Additional context Add any other context about the problem here.