Only pass needed setting to Alphabet

As Alphabet class is static, its methods could be used without
ever calling Alphabet.initialize(_settings) beforehand which would end
in an exception.  Therefor only _shouldUsePinyin settings needed will
be transferred with a given default value.

Wox/App.xaml.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Diagnostics;
 using System.Threading.Tasks;
 using System.Timers;
@@ -53,7 +53,7 @@ namespace Wox
                 _settingsVM = new SettingWindowViewModel();
                 _settings = _settingsVM.Settings;
 
-                Alphabet.Initialize(_settings);
+                Alphabet.Initialize(_settings.ShouldUsePinyin);
 
                 StringMatcher.UserSettingSearchPrecision = _settings.QuerySearchPrecision;