Rephrase 'openstackmanager-securitygrouprule-ranges-help'

Skalman requested review at
https://translatewiki.net/wiki/Thread:Support/About_MediaWiki:Openstackmanager-securitygrouprule-ranges-help/en

Change-Id: I0313562e83464a071d1cfb5430b0565b61b8e8ff