[PATCH] Revert first_weekday removal from en_IE locale

[Florian Weimer]

* Daniil Zhilin:

> Proof: https://commons.wikimedia.org/wiki/File:First_Day_of_Week_World_Map.svg

We need a more official source.  There is no clear majority:

http://www.gov.ie/search/?q="Su Mo Tu We Th Fr Sa"
http://www.gov.ie/search/?q="Mo Tu We Th Fr Sa Su"