Make the inventory_import command log an error message on exception

when it happens in the big try/except block in the middle of handle().
Previously it wasn't doing anything with it, except exiting with a
code of 1.

awx/main/management/commands/inventory_import.py

@@ -1104,7 +1104,8 @@ class Command(BaseCommand):
                 self.inventory_source.status = status
                 self.inventory_source.save(update_fields=['status'])
 
-        if exc and isinstance(exc, CommandError):
+        if exc:
-            sys.exit(1)
+            logger.error(str(exc))
-        elif exc:
+            if isinstance(exc, CommandError):
+                sys.exit(1)
             raise exc