Update CHANGELOG.md

CHANGELOG.md

@@ -14,6 +14,7 @@ IMPROVEMENTS:
 BUG FIXES:
 
   * core: `isotime` is the same time during the entire build. [GH-1153]
+  * builder/openstack: Force IPv4 addresses from address pools [GH-1258]
   * builder/parallels: Do not delete entire CDROM device. [GH-1115]
   * builder/virtualbox-ovf: Supports guest additions options. [GH-1120]
   * builder/vmware: Remote ESXi builder now uploads floppy. [GH-1106]