Delete duplicate quantity SubstanceAmount (#317)

Author: Ferit Tunçer

UnitsNet.Tests/GeneratedCode/SubstanceAmountTestsBase.g.cs

@@ -78,6 +78,7 @@ static UnitSystem()
         /// </summary>
         public UnitSystem() : this(DefaultCulture)
         {
+
         }
 
         // Windows Runtime Component does not allow public methods/ctors with same number of parameters: https://msdn.microsoft.com/en-us/library/br230301.aspx#Overloaded methods