pegasus-db-admin should do checking against the values parsed.

Lets say I have an empty pegasusrc

pegasus-db-admin check -t jdbcrc -c pegasusrc
rocessing properties file pegasusrc...
Traceback (most recent call last):
File "/nfs/asd2/vahi/montage/tutorial/pegasus/pegasus-4.5.0cvs/bin/pegasus-db-admin", line 37, in <module>
main()
File "/nfs/asd2/vahi/montage/tutorial/pegasus/pegasus-4.5.0cvs/lib/python2.7/dist-packages/Pegasus/db/admin/commands.py", line 216, in main
DBAdminCommand().main()
File "/nfs/asd2/vahi/montage/tutorial/pegasus/pegasus-4.5.0cvs/lib/python2.7/dist-packages/Pegasus/command.py", line 104, in main
cmd.main(args)
File "/nfs/asd2/vahi/montage/tutorial/pegasus/pegasus-4.5.0cvs/lib/python2.7/dist-packages/Pegasus/command.py", line 23, in main
self.run()
File "/nfs/asd2/vahi/montage/tutorial/pegasus/pegasus-4.5.0cvs/lib/python2.7/dist-packages/Pegasus/db/admin/commands.py", line 157, in run
adminDB = AdminDB(self.options.config_properties, self.options.db_type, dburi)
File "/nfs/asd2/vahi/montage/tutorial/pegasus/pegasus-4.5.0cvs/lib/python2.7/dist-packages/Pegasus/db/admin/admin_loader.py", line 53, in _init_
"JDBCRC": self._get_jdbcrc_uri(props),
File "/nfs/asd2/vahi/montage/tutorial/pegasus/pegasus-4.5.0cvs/lib/python2.7/dist-packages/Pegasus/db/admin/admin_loader.py", line 90, in _get_jdbcrc_uri
url = url.replace("jdbc:", "")
AttributeError: 'NoneType' object has no attribute 'replace'

A sensible message should be displayed instead of the whole trace