Fix setup_commit_message for proposal bot
Fix setup_commit_message for proposal bot

Fix change I80c7f81b0b7f225fbf1e1564239f40b5df8537d9,
I forgot to change a variable name which resulted in
an invalid change ID.

We need to use the variable CHANGE_ID that in the commit message which
is set a few lines above.

Change-Id: I9aeff5c432397f3cb06808066a76afb12f460fd7

openstack-infra/project-config,dongwenjuan/project-config,Tesora/tesora-project-config,noorul/os-project-config,openstack-infra/project-config,dongwenjuan/project-config,noorul/os-project-config,Tesora/tesora-project-config