doc/go1.8: update timezone database version
doc/go1.8: update timezone database version

Fixes #18623.

Change-Id: Ic965f5f7088c3270adbca7162226be486d1b9b4e
Reviewed-on: https://go-review.googlesource.com/35130
Reviewed-by: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>

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