drop deprecated plot3dPixelRatio from config

Author: archmoj

src/plot_api/plot_api.js

@@ -452,11 +452,6 @@ function setPlotContext(gd, config) {
             }
         }
 
-        // map plot3dPixelRatio to plotGlPixelRatio for backward compatibility
-        if(config.plot3dPixelRatio && !context.plotGlPixelRatio) {
-            context.plotGlPixelRatio = context.plot3dPixelRatio;
-        }
-
         // now deal with editable and edits - first editable overrides
         // everything, then edits refines
         var editable = config.editable;

src/plot_api/plot_config.js

@@ -350,9 +350,7 @@ var configAttributes = {
         min: 1,
         max: 4,
         description: [
-            'Set the pixel ratio during WebGL image export.',
-            'This config option was formerly named `plot3dPixelRatio`',
-            'which is now deprecated.'
+            'Set the pixel ratio during WebGL image export.'
         ].join(' ')
     },