fixes in METNet tool
This MR aims to fix two things in the METNet tool:
- switch to the use of absolute eta in the estimation of PU contribution similar to a previous fix in the METSignificance tool as spotted by @hpacey
- fix the property names of the used METMakers
Maybe @mleigh as developer of the tool can quickly comment if that looks good to him. One thing I'm unsure if it's actually sensible to introduce the first fix as the current networks might also been have trained with the "bugged" pile-up contribution.
Edited by Michael Holzbock