firefox_esr: Update version from 45.5.1 to 45.6.0

Release notes [1]:

> Version 45.6.0, first offered to ESR channel users on December 13,
> 2016
>
> Various security fixes [2]

Add fixes for MFSA 2016-95 [3], also known as:

CVE-2016-9899, CVE-2016-9895, CVE-2016-9897, CVE-2016-9898,
CVE-2016-9900, CVE-2016-9904, CVE-2016-9905, CVE-2016-9901,
CVE-2016-9902, CVE-2016-9893.

[1] https://www.mozilla.org/en-US/firefox/45.6.0/releasenotes/
[2] https://www.mozilla.org/en-US/security/known-vulnerabilities/firefox-esr/#firefoxesr45.6
[3] https://www.mozilla.org/en-US/security/advisories/mfsa2016-95/

firefox_esr.be0

@@ -1,6 +1,6 @@
 #!/bin/env beesh
 
-# BEE_VERSION firefox_esr-45.5.1-0
+# BEE_VERSION firefox_esr-45.6.0-0
 
 #export BEE_TMP_TMPDIR=/dev/shm BEE_TMP_BUILDROOT=/dev/shm/bee-root BEE_MAKEFLAGS='-j80'