fix(cli): handle nil config in EnvSettings.Namespace()

Signed-off-by: Zadkiel AHARONIAN <hello@zadkiel.fr>
(cherry picked from commit 8534663e73)

pkg/cli/environment.go

@@ -275,8 +275,10 @@ func (s *EnvSettings) EnvVars() map[string]string {
 
 // Namespace gets the namespace from the configuration
 func (s *EnvSettings) Namespace() string {
-	if ns, _, err := s.config.ToRawKubeConfigLoader().Namespace(); err == nil {
-		return ns
+	if s.config != nil {
+		if ns, _, err := s.config.ToRawKubeConfigLoader().Namespace(); err == nil {
+			return ns
+		}
 	}
 	if s.namespace != "" {
 		return s.namespace