hg: openjfx/9/rt: 8182761: Change FX milestone to fcs for JDK 9

[kevin.rushforth at oracle.com]

Changeset: bbc24a15f528
Author:    kcr
Date:      2017-06-24 06:05 -0700
URL:       http://hg.openjdk.java.net/openjfx/9/rt/rev/bbc24a15f528

8182761: Change FX milestone to fcs for JDK 9
Reviewed-by: prr, lana

! build.properties