Edge case test fail in shared random code
The test_state_update() test would fail if you run it between 23:30 and
00:00UTC in the following way:
```
FAIL src/test/test_shared_random.c:1230: assert(state->n_protocol_runs == 1): 2 vs 1
[state_update FAILED]
1/1 TESTS FAILED. (0 skipped)
```
The problem is that when you launch the test at 23:30UTC (reveal phase),
sr_state_update() gets called from sr_state_init() and it will prepare
the state for the voting round at 00:00UTC (commit phase). Since we
transition from reveal to commit phase, this would trigger an unwanted phase
transition and increment the n_protocol_runs counter even before the actual test starts.
The solution is to initialize the n_protocol_runs to 0 explicitly in the
beginning of the test, as we do for n_reveal_rounds, n_commit_rounds etc.
issue