Capitalization of 'TimeZone' GUC

Hi all,

I noticed that the 'TimeZone' GUC is displayed in all-lowercase at:
  http://www.postgresql.org/docs/9.1/static/runtime-config-client.html

when it should be camel-cased like 'DateStyle' and 'IntervalStyle'
above it, since that is how the GUC is displayed to users, e.g. as the
column name for 'SHOW timezone;'

Small patch attached.

Josh