version up: golang

Version up for golang from go1.9.1 to go1.9.2

@rafael @kirr @alain.takoudjou

[ kirr: from https://golang.org/doc/devel/release.html#go1.9.minor

go1.9.2 (released 2017/10/25) includes fixes to the compiler, linker, runtime, documentation, go command, and the crypto/x509, database/sql, log, and net/smtp packages. It includes a fix to a bug introduced in Go 1.9.1 that broke go get of non-Git repositories under certain conditions. See the Go 1.9.2 milestone on our issue tracker for details.

@gabriel says they tested go1.9.2 on Caddy ]

/reviewed-on nexedi/slapos!247

component/golang/buildout.cfg

@@ -42,8 +42,8 @@ environment-extra =
 
 [golang19]
 <= golang-common
-url = https://storage.googleapis.com/golang/go1.9.1.src.tar.gz
-md5sum = 27bce1ffb05f4f6bd90d90081e5d4169
+url = https://storage.googleapis.com/golang/go1.9.2.src.tar.gz
+md5sum = 44105c865a1a810464df79233a05a568
 
 # go1.9 needs go1.4 to bootstrap
 environment-extra =