Enabled rule attribute never used

[BrennanConroy]

https://github.com/aspnet/BasicMiddleware/blob/dev/src/Microsoft.AspNetCore.Rewrite/Internal/IISUrlRewrite/UrlRewriteFileParser.cs#L58

@mikaelm12 @muratg @jkotalik

[jkotalik]

That issues doesn't fix the enable rule never being used. It should be added here:
https://github.com/aspnet/BasicMiddleware/blob/dev/src/Microsoft.AspNetCore.Rewrite/Internal/IISUrlRewrite/UrlRewriteRuleBuilder.cs#L31
as a check to see if we should be creating the rule in the first place.

[mikaelm12]

The enabled flag on the builder is actually being used here to determine if each rule should be added

BasicMiddleware/src/Microsoft.AspNetCore.Rewrite/Internal/IISUrlRewrite/UrlRewriteFileParser.cs

Lines 51 to 54 in d57149f

	if (builder.Enabled)
	{
	result.Add(builder.Build());
	}