SF #1063757: fix markup error (had LaTeX markup in the reST source,

oops!).

Doc/lib/liboptparse.tex

@@ -704,7 +704,7 @@ directly.)
 \subsubsection{Defining options\label{optparse-defining-options}}
 
 Each Option instance represents a set of synonymous command-line option
-strings, e.g. programopt{\{}f{\}} and longprogramopt{\{}--file{\}}.  You can
+strings, e.g. \programopt{-f} and \longprogramopt{file}.  You can
 specify any number of short or long option strings, but you must specify
 at least one overall option string.