Merge pull request #328 from avinxshKD/fix/redo-null-guard

fix: add null guard to redo() to match undo() pattern

Author: pradeeban

src/toolbarActions/toolbarFunctions.js

@@ -175,7 +175,7 @@ const undo = (state) => {
     if (getGraphFun(state)) getGraphFun(state).undo();
 };
 const redo = (state) => {
-    getGraphFun(state).redo();
+    if (getGraphFun(state)) getGraphFun(state).redo();
 };
 
 const openShareModal = (state, setState) => {