RD builder fix

Quick fix for a mistake in rdbuilder_thor

• code_dielectron in make_prompt_dielectron_with_brem was commented by mistake, now uncommented.

requested review from @vlisovsk

assigned to @msaur

added RD RTA selection labels

added hlt2 label

approved this merge request

marked this merge request as ready

@thboettc This one is ready, just a small fix following !1297 (merged).

assigned to @rmatev and @thboettc and unassigned @msaur

resolved all threads

merged

mentioned in commit da1e51d8

mentioned in issue #390 (closed)

added bug fix label