spec: undo spec date change introduced by prior commit
spec: undo spec date change introduced by prior commit

I accidentally included a modified spec in
https://go-review.googlesource.com/27290 .
Remove that change.

Change-Id: Icb62fe829072860e9eb74865d21e06f30efcfd26
Reviewed-on: https://go-review.googlesource.com/27357
Reviewed-by: Robert Griesemer <a6752097faebf1f02d80107d77a9be009089afe3@golang.org>

polyverse-security/go,akutz/go,cloudflare/go,momchil-velikov/go,CAFxX/go,cloudflare/go,cloudflare/go,linux-on-ibm-z/go,suncycheng/go,derekmarcotte/go,Cofyc/go,goodlang/good,akutz/go,vsekhar/elastic-go,ImJasonH/go,CAFxX/go,derekmarcotte/go,golang/go,nawawi/go,nawawi/go,derekmarcotte/go,polyverse-security/go,nawawi/go,nawawi/go,suncycheng/go,derekmarcotte/go,nawawi/go,suncycheng/go,vsekhar/elastic-go,christopher-henderson/Go,Cofyc/go,golang/go,CAFxX/go,linux-on-ibm-z/go,goodlang/good,vsekhar/elastic-go,golang/go,codestation/go,CAFxX/go,nawawi/go,golang/go,nawawi/go,akutz/go,polyverse-security/go,derekmarcotte/go,polyverse-security/go,akutz/go,polyverse-security/go,linux-on-ibm-z/go,momchil-velikov/go,vsekhar/elastic-go,linux-on-ibm-z/go,CAFxX/go,josharian/go,Cofyc/go,ImJasonH/go,vsekhar/elastic-go,Cofyc/go,codestation/go,momchil-velikov/go,goodlang/good,momchil-velikov/go,golang/go,ImJasonH/go,codestation/go,josharian/go,suncycheng/go,akutz/go,josharian/go,codestation/go,CAFxX/go,akutz/go,derekmarcotte/go,codestation/go,CAFxX/go,Cofyc/go,cloudflare/go,momchil-velikov/go,linux-on-ibm-z/go,josharian/go,linux-on-ibm-z/go,goodlang/good,josharian/go,Cofyc/go,josharian/go,ImJasonH/go,goodlang/good,vsekhar/elastic-go,josharian/go,codestation/go,momchil-velikov/go,golang/go,cloudflare/go,momchil-velikov/go,cloudflare/go,nawawi/go,vsekhar/elastic-go,cloudflare/go,polyverse-security/go,polyverse-security/go,linux-on-ibm-z/go,ImJasonH/go,golang/go,linux-on-ibm-z/go,derekmarcotte/go,akutz/go,ImJasonH/go,suncycheng/go,josharian/go,golang/go,codestation/go,derekmarcotte/go,akutz/go,goodlang/good,Cofyc/go,suncycheng/go,CAFxX/go,ImJasonH/go,polyverse-security/go,suncycheng/go,momchil-velikov/go,codestation/go,vsekhar/elastic-go,goodlang/good,Cofyc/go,ImJasonH/go,cloudflare/go,goodlang/good,suncycheng/go