Improve Irish translation ga-IE

[damienbod]

https://github.com/damienbod/IdentityServer4AspNetCoreIdentityTemplate/tree/master/content/StsServerIdentity/Resources
@ Niall Merrigan ‏

[damienbod]

https://github.com/damienbod/IdentityServer4AspNetCoreIdentityTemplate/blob/master/translations_ga_ie.xlsx

Or direct in the resx