Merge branch 'jm/svn-pushmergeinfo-fix' into maint

"git svn dcommit" did not take into account the fact that a svn+ssh:// URL with a username@ (typically used for pushing) refers to the same SVN repository without the username@ and failed when svn.pushmergeinfo option is set. * jm/svn-pushmergeinfo-fix: git-svn: fix svn.pushmergeinfo handling of svn+ssh usernames.