Poller overrun warning message is badly worded

**Describe the bug**
```
POLLER: Poller[Main Poller] WARNING: There are '1' detected as overrunning a polling cycle, please investigate
```

**Expected behavior**
The message should read something like:
```
POLLER: Poller[Main Poller] WARNING: There are 1 pollers detected as overrunning a polling cycle, please investigate
```
