Bug#972813: xournal FTBFS: wrongly declared R³

[Barak A. Pearlmutter]

"Rules-Requires-Root?"
"No"
"You Worm. You Scum. You Lowly User. REJECTED!!! Upper Case Is
Reserved For Your Betters. Do You Think You Are My Equal?"
"no."
"What Was That? Did You Just Use Punctuation? Do You Deserve To Use
Punctuation?"
"nope"
"What!?!? You Need Discipline. A GNU Kind Of Discipline! Now Rewrite
This Package In Gnat Ada. Using Ed(1)."