[meta.reflection.queries] Delete mistaken "Throws:" element.

This was added accidentally in
b679e4b because I misread the paper.

Author: tkoeppe

source/meta.tex

@@ -4838,11 +4838,6 @@
 class template, or
 an alias template.
 Otherwise, \tcode{false}.
-
-\pnum
-\throws
-\tcode{meta::exception} unless
-\tcode{has_template_arguments(r)} is \tcode{true}.
 \end{itemdescr}
 
 \indexlibraryglobal{template_of}%