Patch the end before starting new run of given detector

If for some reason we don't assign the proper endtime to the previous run, make sure it's at least before the new document is inserted. For example

| run | det | start | stop | 
| - | - | - | - |
| 1 | tpc | 00.00 | None | 
| 2 | nv | 00.30 | 01.15 |
| 3 | tpc | 01.00 | None | 

That run 1 gets endtime 01.00 and is tagged messy