improve paramiko integration, replace .mesage for exceptions with str(exc)
diff --git a/wally/report.py b/wally/report.py
index 85ac388..461c2a0 100644
--- a/wally/report.py
+++ b/wally/report.py
@@ -169,6 +169,6 @@
         di = get_disk_info(processed_results)
         render_html(path, di, lab_info)
     except Exception as exc:
-        logger.error("Failed to generate html report:" + exc.message)
+        logger.error("Failed to generate html report:" + str(exc))
     else:
         logger.info("Html report were stored in " + path)