[time.syn] Fix indentation (cplusplus#7535)

Author: Andreas-Krug

source/time.tex

@@ -857,7 +857,7 @@
   // \ref{time.parse}, parsing
   template<class charT, class Parsable>
     @\unspec@
-     parse(const charT* fmt, Parsable& tp);
+      parse(const charT* fmt, Parsable& tp);
   template<class charT, class traits, class Alloc, class Parsable>
     @\unspec@
       parse(const basic_string<charT, traits, Alloc>& fmt, Parsable& tp);