Fixed bug causing flickering and excessive refreshing.

DisplayESP32.ino

@@ -571,6 +571,7 @@ class Screen{
 //This can be avoided using pointers to the variable to plot in the graph
   void graphAssignValue(int graphIndex, double value){
     this->graph[graphIndex].assignValue(value);
+    if(this->currentScreen == graphIndex && this->contentType == 1)
     this->redraw = true;
   }
 
@@ -641,6 +642,7 @@ class Screen{
       this->currentScreen = this->modifier[this->currentScreen].getPreviousScreen();
       this->contentType = this->modifier[this->currentScreen].getPreviousContentType();
     }
+    this->redraw = true;
   }
 
 //These methods control the plus and minus button actions
@@ -651,6 +653,7 @@ class Screen{
     else if(contentType == 2){
       this->modifier[currentScreen].increaseValue();
     }
+    this->redraw = true;
   }
 
   void minusAction(){
@@ -660,6 +663,7 @@ class Screen{
     else if(contentType == 2){
       this->modifier[currentScreen].decreaseValue();
     }
+    this->redraw = true;
   }
   
 };