Make 'svnadmin verify --keep-going' always show an error summary.
Previously, the error summary was not displayed if the --quiet option was used in combination with --keep-going. The purpose of the --quiet option is to suppress verbose progress output. The purpose of the --keep-going option is to support long-running and non-interactive verification of one or more repositories. In which case instant progress output is of low importance but a summary of errors detected is invaluable so it makes little sense to suppress the summary.
* subversion/svnadmin/svnadmin.c (subcommand_verify): Display the --keep-going error summary regardless of whetehr the --quiet option was passed.