Low: pgsql: fix grep failure when using pacemaker 1.1.10

I fixed regex because "crm_mon" doesn't display meaningless IDs when using pacemaker 1.1.10.

before
```
pgsql:0   (ocf::heartbeat:pgsql): Started
```

after
```
pgsql   (ocf::heartbeat:pgsql): Started
```


ref : https://github.com/ClusterLabs/pacemaker/commit/b3f5b2de2906d52e3cb888f08143fa0ec7c48ce3#tools/crm_mon.c