fix: warn on unavailable lazy load not throw (#1400)

* fix: warn on unavailable lazy load not throw

* and a default

src/posthog-surveys.ts

@@ -265,8 +265,9 @@ export class PostHogSurveys {
 
     // this method is lazily loaded onto the window to avoid loading preact and other dependencies if surveys is not enabled
     private _canActivateRepeatedly(survey: Survey) {
-        if (isNullish(assignableWindow.__PosthogExtensions__.canActivateRepeatedly)) {
+        if (isNullish(assignableWindow.__PosthogExtensions__?.canActivateRepeatedly)) {
             logger.warn(LOGGER_PREFIX, 'canActivateRepeatedly is not defined, must init before calling')
+            return false // TODO does it make sense to have a default here?
         }
         return assignableWindow.__PosthogExtensions__.canActivateRepeatedly(survey)
     }