proofloc.py: "Next Obligation" also starts a proof

...and "Defined" can end one.
Status Job ID Name Coverage
  Build
passed #47897
1.9.0-coq-8.10

00:03:27

passed #47896
1.9.0-coq-8.9

00:03:33

passed #47898
allowed to fail
1.9.0-coq-dev

00:03:21

passed #47899
allowed to fail
latest-coq-8.10

00:02:11

 
  Process
passed #47901
doc

00:00:33

passed #47902
proof-length

00:00:15

passed #47904
proof-state

00:02:04

passed #47900
validate

00:01:01

failed #47903
proof-state

00:01:11