fixed labels parsing for escaped dot sequences

[mstrouhal]

Hello!

I have found a problem occurring when you are using queries with escaped dots.

If you use \. sequence in your DNS query, it is not parsed correctly as single label, but split into two labels, causing character \ to be in the end of previous label and escaped by another \, resulting in \\..

That is something else then you wanted to query in the first place.

These few lines of code are fixing the problem.