ConfigParser still referenced in pegasus-worker CLI scripts

There are lingering references to the `ConfigParser` module in pegasus-worker scripts, this should be update to user `configparser` for python3.

```
$ git grep -E "^ *(from|import) ConfigParser" packages/
packages/pegasus-worker/src/Pegasus/cli/pegasus-globus-online-init.py:from ConfigParser import ConfigParser
packages/pegasus-worker/src/Pegasus/cli/pegasus-transfer.py: import ConfigParser as configparser
```