apps/app_dial: Fix Dial 'z' option

The 'z' option is supposed to disable the dial timeout in the case of a call
forward. Unfortunately, the wrong timeout timer was passed to the do_forward
function, resulting in the option not working.

ASTERISK-24225 #close
Reported by: dimitripietro
Tested by: dimitripietro
patches:
  jira_asterisk_24225_v1.8.patch uploaded by rmudgett (License 5621)
  jira_asterisk_24225_v11.patch uploaded by rmudgett (License 5621)
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Merged revisions 421232 from http://svn.asterisk.org/svn/asterisk/branches/1.8
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Merged revisions 421233 from http://svn.asterisk.org/svn/asterisk/branches/11
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Merged revisions 421234 from http://svn.asterisk.org/svn/asterisk/branches/12
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Merged revisions 421235 from http://svn.asterisk.org/svn/asterisk/branches/13


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@421236 65c4cc65-6c06-0410-ace0-fbb531ad65f3