Removes unneeded build tags from darwin and windows files

http/open_browser_darwin.go

@@ -1,4 +1,4 @@
-// +build darwin
+// This will build for osx without a build tag based on the filename
 
 package http
 

http/open_browser_windows.go

@@ -1,5 +1,5 @@
-// +build windows
-
+// This will only build for windows based on the filename
+// no build tag required
 package http
 
 import "os/exec"