Regression Ui: fix invalid type cast.

test/regression/ai_regression_ui.py

@@ -63,7 +63,7 @@ def log( sev, msg ):
         logEntry = logEntry + "[WARN]: "
     elif sev == 2:
         logEntry = logEntry + "[ERR] : "
-    logEntry = logEntry + msg
+    logEntry = logEntry + str( msg )
     print( logEntry )
 
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