[oe] Prefer wget 1.12 by default

[Khem Raj]

Hi

Right now we use wget_1.9.1.bb if someone did not pin wget to other
versions. We have recipes from later versions
like 1.12 but they have DEFAULT_PREFERENCE="-1"
1.9.1 has problems building with -j > 1 as many times build break with
Text File busy errors.

I would like to propose that we upgrade defaults to 1.12. If someone
has objections here is your chance.

Thanks
-Khem