Initialise local POD 'launched' variable in show_help()

'launched' local POD (Plain Old Data) variable was left uninitialised,
but was set in both the try and catch clauses.  Best practice is to
initialise when defined, so do that instead.  Cosmetic change.
4 jobs for master in 19 minutes and 48 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Build
passed #232209
centos_build

00:04:04

passed #232210
ubuntu_build

00:07:02

 
  Test
passed #232211
centos_test

00:08:49

passed #232212
ubuntu_test

00:12:45