Revision 1882157

In --help output, do not suggest the -v option if no global options exist.

While e.g. 'svn --help -v update' prints a section about global options,
other commands such as svnadmin or svnrdump return an error if the -v
option is used, even though their --help messages were suggesting that
more options would be presented with -v.

Reported by: wib_jonas on the #svn IRC channel
https://colabti.org/irclogger/irclogger_log/svn?date=2020-09-30#l34

* subversion/libsvn_subr/opt.c
  (print_command_info3): Only print a hint about using the -v option if
   the caller has in fact defined a set of global options.