fix svg when secondYAxis, refs graphite-project/graphite-web#68
fix svg when secondYAxis, refs graphite-project/graphite-web#68

Krylon360/evernote-graphite-web,evernote/graphite-web,evernote/graphite-web,Krylon360/evernote-graphite-web,Krylon360/evernote-graphite-web,Talkdesk/graphite-web,Talkdesk/graphite-web,Talkdesk/graphite-web,Talkdesk/graphite-web,Krylon360/evernote-graphite-web,Talkdesk/graphite-web,Talkdesk/graphite-web,evernote/graphite-web,Krylon360/evernote-graphite-web,Krylon360/evernote-graphite-web,evernote/graphite-web,evernote/graphite-web