WebComment: escape review "title"

* Escapes title of a review when displaying the review form
  with some initial value (complements 28d3555 for maint-1.0 and
  above).

Reported-by: Friedrich Hust <Friedrich.Hust@rwth-aachen.de>
Reviewed-by: Tibor Simko <tibor.simko@cern.ch>