net/url: simplify values Get

src/net/url/url.go

@@ -883,14 +883,10 @@ type Values map[string][]string
 // the empty string. To access multiple values, use the map
 // directly.
 func (v Values) Get(key string) string {
-	if v == nil {
-		return ""
+	if vs := v[key]; len(vs) != 0 {
+		return vs[0]
 	}
-	vs := v[key]
-	if len(vs) == 0 {
-		return ""
-	}
-	return vs[0]
+	return ""
 }
 
 // Set sets the key to value. It replaces any existing