Fix PgEU donation text to match reality

Fix PgEU donation text to match reality

The donations link for PgEU can in fact not be used to donate funds
earmarked for any particular usergroup or activity, so remove the
wording which implied that.

This also fixes a missing </p> tag in an adjacent part of the page,
no visible changes expected since browsers are very good at injecting
these themselves.

Reviewed-by: Magnus Hagander
Discussion: http://postgr.es/m/30D2592C-B495-42A7-B908-33C36793E773@yesql.se