Sharing links can't be used to generate further sharing links

[jamesharle]

I'm submitting a ...

Check one of the following options with "x" and add the appropriate label to the issue as well

[X] Bug report 
[ ] Regression (behaviour that used to work and stopped working in a new release)

Describe the Issue When user accesses the Hub via a Hub-Generated link, then configures an indicator within global picture, then shares this via the chart button (as configured), a broken link is generated.

To Reproduce Replace the content below with the steps to reproduce the behaviour.

1. Go to 'http://data.devinit.org/global-picture/'
2. Click on 'share this chart'
3. Copy link
4. Follow link
5. Click on 'Share this chart'
6. Copy link
7. Follow link
8. See error

Expected Behaviour The correct behaviour would see the button producing a link based on the chart settings rather than the present URL, since the present URL will not always be what is required.

Screenshots/GIF If applicable, add screenshots or a GIF to help explain your problem.

Desktop (please complete the following information):

• OS: [Windows 7]
• Browser [Chrome]
• Version [69.0.3497.100]

Smartphone (please complete the following information):

• Device: [e.g. iPhone6]
• OS: [e.g. iOS8.1]
• Browser [e.g. stock browser, safari]
• Version [e.g. 22]

Environment/Server:

- [ ] Production
- [ ] Staging
- [ ] Test
- [ ] Development

Additional Context Add any other context about the problem here.

Requested Delivery Date: dd/MMM/YYYY