templates/rss/error.tmpl

patch: simplify Boolean expression slightly

The context variable is either True, False or None. Abbreviate it as C
and we get the following truth table where the second column is the
original expression and the third column is the new expression:

  C     | C or C == None | C is not False
  True  | True           | True
  False | False          | False
  None  | True           | True

{header}
    <title>Error</title>
    <description>Error</description>
    <item>
      <title>Error</title>
      <description>{error|escape}</description>
      <guid>http://www.selenic.com/mercurial/#error</guid>
    </item>
  </channel>
</rss>