when reverting PRC, nonexistent settings can crash interpreter

[d-w-moore]

The script

#script: autoload_issue.py
import irods   # <-- auto load of settings happen here if enabled
print ("GOT HERE!")

when run as

$ PYTHON_IRODSCLIENT_CONFIGURATION_PATH="" python autoload_issue.py

aborts the program on the import if, for example, an attempt is made to load a nonexistent setting.

This can happen naturally when reverting to past python-irodsclient versions not recognizing those settings, or jumping around to different git branches.

Instead of raising an exception in these cases, it should be merely logged as an error.