Disable specified version of NUnit

Author: asbjornu

src/GitVersion.sln.DotSettings

@@ -552,6 +552,7 @@ II.2.12 <HandlesEvent />
 	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002EJavaScript_002ECodeStyle_002ESettingsUpgrade_002EJsParsFormattingSettingsUpgrader/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002EJavaScript_002ECodeStyle_002ESettingsUpgrade_002EJsWrapperSettingsUpgrader/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/Environment/UnitTesting/DisabledProviders/=NUnit3x/@EntryIndexedValue">False</s:Boolean>
+	<s:Boolean x:Key="/Default/Environment/UnitTesting/NUnitProvider/UseCustomNUnit/@EntryValue">False</s:Boolean>
 	<s:Boolean x:Key="/Default/Environment/UnitTesting/SeparateAppDomainPerAssembly/@EntryValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/Environment/UnitTesting/ShadowCopy/@EntryValue">False</s:Boolean>