PHPTIMEZONE variable has trailing newline character following an install (?)

When FreePBX 13 is initially installed, it gets the time zone from /etc/timezone.
etc/timezone contains a trailing newline character (under Debian 8, at least). It appears this trailing newline character is making it into the PHPTIMEZONE variable:

/var/lib/asterisk/bin/freepbx_setting PHPTIMEZONE America/Los_Angeles

trying to run as user asterisk:

[PHPTIMEZONE] changed from previous value: [America/Chicago
] to new value: [America/Los_Angeles]

/var/lib/asterisk/bin/freepbx_setting PHPTIMEZONE America/Chicago

trying to run as user asterisk:

[PHPTIMEZONE] changed from previous value: [America/Los_Angeles] to new value: [America/Chicago]