Respect TERM_CHILD setting when not forking

The behavior of TERM_CHILD is desirable even when there is no child
process (using FORK_PER_JOB=false). This patch makes non-forking Resque
workers behave the same way when sent a TERM signal.
Fix travis build failure on 1.8.7
Merge pull request #1174 from ggilder/1-x-stable

Respect TERM_CHILD setting when not forking