Moved removeAllListeners and added existence check

Author: mdtusz

src/plot_api/plot_api.js

@@ -941,7 +941,6 @@ Plotly.redraw = function(gd) {
 Plotly.newPlot = function (gd, data, layout, config) {
     gd = getGraphDiv(gd);
     plots.purge(gd);
-    gd.removeAllListeners();
     return Plotly.plot(gd, data, layout, config);
 };
 

src/plots/plots.js

@@ -712,6 +712,9 @@ plots.purge = function(gd) {
     delete gd.numboxes;
     delete gd._hoverTimer;
     delete gd._lastHoverTime;
+
+    // remove all event listeners
+    if(gd.removeAllListeners) gd.removeAllListeners();
 };
 
 plots.style = function(gd) {