net/http/pprof: remove comments pointing to gperftools
net/http/pprof: remove comments pointing to gperftools

The version of pprof in gperftools has been deprecated.
No need to have a pointer to that version since go tool pprof
is included with the Go distro.

Change-Id: I6d769a68f64280f5db89ff6fbc67bfea9c8f1526
Reviewed-on: https://go-review.googlesource.com/24509
Reviewed-by: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>

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