[LNT] Python 3 support: adapt regex for div by 0 msg

[thopre]

Summary

Test server/ui/V4Pages.py checks that the /explode page leads to a
division by zero exception message. However the exception message has
changed between Python 2 and Python 3 so this commit adapts the regex to
catch both texts.

[thopre]

Rebase earlier

[thopre]

Committed as f243f1421819bf5490fd68d9b22d336c251fe5bb

tests/server/ui/V4Pages.py

def main():
 
     # Make sure the new option does not break anything
     check_html(client, '/db_default/v4/nts/graph?switch_min_mean=yes&plot.0=1.3.2&submit=Update')
     check_json(client, '/db_default/v4/nts/graph?switch_min_mean=yes&plot.0=1.3.2&json=true&submit=Update')
     check_html(client, '/db_default/v4/nts/graph?switch_min_mean=yes&plot.0=1.3.2')
     check_json(client, '/db_default/v4/nts/graph?switch_min_mean=yes&plot.0=1.3.2&json=true')
     app.testing = False
     error_page = check_html(client, '/explode', expected_code=500)
-    assert "integer division or modulo by zero" in error_page.get_data(as_text=True)
+    assert re.search("division (or modulo )?by zero",
+                     error_page.get_data(as_text=True))
 
     error_page = check_html(client, '/gone', expected_code=404)
     assert "test" in error_page.get_data(as_text=True)
 
     check_html(client, '/sleep?timeout=0', expected_code=200)
 
     check_html(client, '/db_default/summary_report')