vendor: update vendored upspin.io to e441518

Fix upspin/upspin#584

Change-Id: Ibc27aad532d482033674be2aefa5834bb71fc343
Reviewed-on: https://upspin-review.googlesource.com/18920
Reviewed-by: David Presotto <presotto@gmail.com>
diff --git a/Gopkg.lock b/Gopkg.lock
index 5bf7d6c..6afae81 100644
--- a/Gopkg.lock
+++ b/Gopkg.lock
@@ -277,7 +277,7 @@
     "valid",
     "version"
   ]
-  revision = "2e37c3b2c427b239f286de76ee3379ece3b2a636"
+  revision = "e44151808db2e821ace484960836205230adb05e"
 
 [solve-meta]
   analyzer-name = "dep"
diff --git a/vendor/upspin.io/cloud/https/https.go b/vendor/upspin.io/cloud/https/https.go
index 3b8b501..d565d2d 100644
--- a/vendor/upspin.io/cloud/https/https.go
+++ b/vendor/upspin.io/cloud/https/https.go
@@ -125,8 +125,12 @@
 		}
 		hosts = []string{host}
 	}
+	addr := flags.HTTPSAddr
+	if flags.InsecureHTTP {
+		addr = flags.HTTPAddr
+	}
 	return &Options{
-		Addr:             flags.HTTPSAddr,
+		Addr:             addr,
 		HTTPAddr:         flags.HTTPAddr,
 		LetsEncryptCache: flags.LetsEncryptCache,
 		LetsEncryptHosts: hosts,