Fix documentation for have_spicy [skip CI]

The continued line was incorrectly marked up (as a plain comment instead
of a Zeekygen comment) which caused only half of the docstring to be
rendered by Zeekygen.

src/zeek.bif

@@ -5340,7 +5340,7 @@ function has_module_events%(group: string%) : bool
 	%}
 
 ## Returns true if Zeek was built with support for using Spicy analyzers (which
-# is the default).
+## is the default).
 function have_spicy%(%) : bool
 	%{
 #ifdef HAVE_SPICY