net: fix misrecongnization of IPv6 zone on Windows
net: fix misrecongnization of IPv6 zone on Windows

Fixes #15463.

Change-Id: Ic85886861c650ffcb71240d847941534152b92bc
Reviewed-on: https://go-review.googlesource.com/22540
Run-TryBot: Mikio Hara <e2f4d2eec1d9a1f781345cdd7260d7d52e6468ae@gmail.com>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>

codestation/go,theif519/go,momchil-velikov/go,theif519/go,momchil-velikov/go,golang/go,CAFxX/go,josharian/go,CAFxX/go,goodlang/good,vsekhar/elastic-go,akutz/go,momchil-velikov/go,josharian/go,vsekhar/elastic-go,4ad/go,ImJasonH/go,josharian/go,theif519/go,momchil-velikov/go,4ad/go,polyverse-security/go,golang/go,polyverse-security/go,suncycheng/go,goodlang/good,nawawi/go,theif519/go,akutz/go,akutz/go,4ad/go,4ad/go,cloudflare/go,ganboing/go-esx,polyverse-security/go,codestation/go,linux-on-ibm-z/go,ImJasonH/go,CAFxX/go,ganboing/go-esx,goodlang/good,linux-on-ibm-z/go,momchil-velikov/go,vsekhar/elastic-go,ganboing/go-esx,vsekhar/elastic-go,akutz/go,nawawi/go,Cofyc/go,codestation/go,codestation/go,suncycheng/go,momchil-velikov/go,golang/go,4ad/go,derekmarcotte/go,linux-on-ibm-z/go,Cofyc/go,ImJasonH/go,ganboing/go-esx,cloudflare/go,CAFxX/go,linux-on-ibm-z/go,derekmarcotte/go,codestation/go,nawawi/go,vsekhar/elastic-go,theif519/go,derekmarcotte/go,goodlang/good,codestation/go,golang/go,ganboing/go-esx,CAFxX/go,goodlang/good,ImJasonH/go,linux-on-ibm-z/go,derekmarcotte/go,ganboing/go-esx,4ad/go,nawawi/go,polyverse-security/go,Cofyc/go,cloudflare/go,akutz/go,momchil-velikov/go,ImJasonH/go,cloudflare/go,suncycheng/go,Cofyc/go,suncycheng/go,josharian/go,ImJasonH/go,derekmarcotte/go,christopher-henderson/Go,theif519/go,4ad/go,golang/go,momchil-velikov/go,ImJasonH/go,josharian/go,Cofyc/go,cloudflare/go,akutz/go,CAFxX/go,Cofyc/go,CAFxX/go,cloudflare/go,linux-on-ibm-z/go,ImJasonH/go,theif519/go,josharian/go,CAFxX/go,4ad/go,codestation/go,goodlang/good,suncycheng/go,akutz/go,Cofyc/go,ganboing/go-esx,golang/go,linux-on-ibm-z/go,goodlang/good,polyverse-security/go,derekmarcotte/go,theif519/go,golang/go,linux-on-ibm-z/go,nawawi/go,polyverse-security/go,golang/go,josharian/go,vsekhar/elastic-go,goodlang/good,derekmarcotte/go,josharian/go,vsekhar/elastic-go,Cofyc/go,nawawi/go,suncycheng/go,vsekhar/elastic-go,suncycheng/go,derekmarcotte/go,nawawi/go,nawawi/go,cloudflare/go,ganboing/go-esx,polyverse-security/go,cloudflare/go,akutz/go,polyverse-security/go,codestation/go,suncycheng/go