reflect: add URL scheme for godoc hyperlinking

Adding the "https://" scheme allows godoc to properly detect
the URL and provide a hyperlink for it.

Change-Id: I76dc309368c86975de01bc6e6e9196037b2114d7
Reviewed-on: https://go-review.googlesource.com/66570Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/reflect/type.go

@@ -212,7 +212,7 @@ type Type interface {
 // t.FieldByName("x") is not well defined if the struct type t contains
 // multiple fields named x (embedded from different packages).
 // FieldByName may return one of the fields named x or may report that there are none.
-// See golang.org/issue/4876 for more details.
+// See https://golang.org/issue/4876 for more details.
 
 /*
  * These data structures are known to the compiler (../../cmd/internal/gc/reflect.go).