cubicweb #2712042 backtrace output is not properly HTML escaped [done]

Exceptions that contain repr()ed class output will be printed as-is in the HTML output which browsers will try to interpret as HTML tags.

The output should be sanitized to make sure it is displayed properly.

prioritynormal
typebug
done in3.16.1
load0.100
load left0.000
closed by#db3164d09765 [etwist] Properly escape traceback output (closes #2712042)