Fix "undefined .nodetype" kinda error

packages/morph/src/morph.js

@@ -168,8 +168,8 @@ export function morph(from, toHtml, options) {
             }
 
             // Handle conditional markers (presumably added by backends like Livewire)...
-            let isIf = node => node.nodeType === 8 && node.textContent === ' __BLOCK__ '
-            let isEnd = node => node.nodeType === 8 && node.textContent === ' __ENDBLOCK__ '
+            let isIf = node => node && node.nodeType === 8 && node.textContent === ' __BLOCK__ '
+            let isEnd = node => node && node.nodeType === 8 && node.textContent === ' __ENDBLOCK__ '
 
             if (isIf(currentTo) && isIf(currentFrom)) {
                 let newFromChildren = []