Fix null pointer bug from commit 7928fac3ce. In this context the options object is in "this", not workspace. (#692)

core/workspace_svg.js

@@ -360,7 +360,7 @@ Blockly.WorkspaceSvg.prototype.addFlyout_ = function() {
     disabledPatternId: this.options.disabledPatternId,
     parentWorkspace: this,
     RTL: this.RTL,
-    oneBasedIndex: workspace.options.oneBasedIndex,
+    oneBasedIndex: this.options.oneBasedIndex,
     horizontalLayout: this.horizontalLayout,
     toolboxPosition: this.options.toolboxPosition
   };