[ issue 1334 ] Fixed

Since we are competing for minimalistic bug fixes (see
https://github.com/agda/agda/commit/b18d100d7457dfe05ba58f39e8b075b240fb5c91#commitcomment-8410366)
I introduce my candidate: -1 whitespace! :-)

Seriously, I don't understand why deleting one whitespace inside a
comment fixed the issue.

I guess some parsing issue was fixed in GHC > 7.4.2.

Cherry-picked from fea7f1457bf8ee18fd51988b8a86b1ee0f441d4b.
Merge branch 'maint-2.4.2'