Removing duplicate/illogical code spotted by Martin V.

* HDC SLU – conditions for 'arrival_time_rel' made more logical
  (will maybe accept a some more variants, but all of them should
  be reasonable)

* NLG templates – removed a duplicate template + fixed a syntax
  error in the remaining copy (the template currently is not
  used anyway)
Merge pull request #66 from UFAL-DSG/fixes_by_mv

Removing duplicate/illogical code spotted by Martin V.