Last fixes for 0.0.1

- fix prometheus request error
- remove console.log
- bring back drawSimpleColorLegend

src/color_mode_discrete.js

@@ -72,6 +72,9 @@ export class ColorModeDiscrete {
   }
 
   updateCardsValuesHasColorInfo() {
+    if (!this.panelCtrl.cardsData) {
+      return
+    }
     this.panelCtrl.cardsData.noColorDefined = false;
     let cards = this.panelCtrl.cardsData.cards;
     for (let i=0; i<cards.length; i++) {