Bump viper version, fix nobrowser (#1991)

vendor/github.com/spf13/afero/regexpfs.go

@@ -60,6 +60,13 @@ func (r *RegexpFs) Chmod(name string, mode os.FileMode) error {
 	return r.source.Chmod(name, mode)
 }
 
+func (r *RegexpFs) Chown(name string, uid, gid int) error {
+	if err := r.dirOrMatches(name); err != nil {
+		return err
+	}
+	return r.source.Chown(name, uid, gid)
+}
+
 func (r *RegexpFs) Name() string {
 	return "RegexpFs"
 }
@@ -126,6 +133,9 @@ func (r *RegexpFs) Open(name string) (File, error) {
 		}
 	}
 	f, err := r.source.Open(name)
+	if err != nil {
+		return nil, err
+	}
 	return &RegexpFile{f: f, re: r.re}, nil
 }