MFH: r404692

www/firefox-esr: update to 38.5.2

Changes: https://hg.mozilla.org/releases/mozilla-esr38/rev/b8244a3f55e1
Security: 2c2d1c39-1396-459a-91f5-ca03ee7c64c6
Approved by: ports-secteam (miwi)