Fix bug with indent whitespace

[Konard]

Reproducible example:

Protocols.Lino/csharp/Platform.Protocols.Lino.Tests/ParserTests.cs

Lines 51 to 60 in be700ac

	public static void BugTest2()
	{
	var source = @"father (lovesMom: loves mom)
	son lovesMom
	daughter lovesMom
	all (love mom)";
	var links = (new Platform.Protocols.Lino.Parser()).Parse(source);
	var target = links.Format();
	Assert.Equal(source,target);
	}

Possible place of the problem:

Protocols.Lino/csharp/Platform.Protocols.Lino/Parser.peg

Lines 23 to 25 in be700ac

	INDENTATION = spaces:" "* &{ spaces.Count == state["Indentation"] }
	INDENT = #{ state["Indentation"] += 4; }
	UNDENT = #{ state["Indentation"] -= 4; }