Correctly handle clicking cancel on go to dialog

src/web/InputWaiter.mjs

@@ -1381,7 +1381,11 @@ class InputWaiter {
      */
     async goToTab() {
         const inputNums = await this.getInputNums();
-        const tabNum = parseInt(window.prompt(`Enter tab number (${inputNums.min} - ${inputNums.max}):`, this.getActiveTab().toString()), 10);
+        let tabNum = window.prompt(`Enter tab number (${inputNums.min} - ${inputNums.max}):`, this.getActiveTab().toString());
+
+        if (tabNum === null) return;
+        tabNum = parseInt(tabNum, 10);
+
         this.changeTab(tabNum, this.app.options.syncTabs);
     }
 

src/web/OutputWaiter.mjs

@@ -797,8 +797,12 @@ class OutputWaiter {
      */
     goToTab() {
         const min = this.getSmallestInputNum(),
-            max = this.getLargestInputNum(),
+            max = this.getLargestInputNum();
-            tabNum = parseInt(window.prompt(`Enter tab number (${min} - ${max}):`, this.getActiveTab().toString()), 10);
+
+        let tabNum = window.prompt(`Enter tab number (${min} - ${max}):`, this.getActiveTab().toString());
+        if (tabNum === null) return;
+        tabNum = parseInt(tabNum, 10);
+
         if (this.outputExists(tabNum)) {
             this.changeTab(tabNum, this.app.options.syncTabs);
         }