Fix typo in prolog compile script

As found by codespell

(cherry picked from commit 4c3b579)

Author: vmcj

sql/files/defaultdata/plg/compile.plg

@@ -4,7 +4,7 @@
 :- dynamic(loading/1).
 :- asserta(loading(0)).
 
-% The first hook is for detectin
+% The first hook is for detecting
 % loading state
 
 user:message_hook(Term, _, _) :-