Fix of k8s shorter segment

My latest PR #676 seemed to have been incompatible with #661 - I did my PR on top of master instead of next. This one is done on top of next and should fix the current not so great state of next (prints nothing). Sorry!

powerlevel9k.zsh-theme

@@ -1430,11 +1430,11 @@ prompt_kubecontext() {
 
     local k8s_final_text=""
 
-    if [[ "$k8s_context" == "k8s_namespace" ]]; then
+    if [[ "$cur_ctx" == "cur_namespace" ]]; then
       # No reason to print out the same identificator twice
-      k8s_final_text="$k8s_context"
+      k8s_final_text="$cur_ctx"
     else
-      k8s_final_text="$k8s_context/$k8s_namespace"
+      k8s_final_text="$cur_ctx/$cur_namespace"
     fi
 
     "$1_prompt_segment" "$0" "$2" "magenta" "white" "$k8s_final_text" "KUBERNETES_ICON"