Marking contacts as not a duplicate on merge screen loses group context

• Run a dedupe rule
• Specify a group to run it on
• On the merge list screen, note that 50 (for example) duplicates are found
• Click to 'merge' the first pair
• Click to mark them as 'Not a duplicate'
• You are returned to the merge list screen, but the group filter is no longer applied - there are now 500,000 duplicates and your database might have crashed.

Fix criteria:
Clicking 'not a duplicate' should return you to the list filtered by the group it was originally filtered by.