fix: Correct comparison for typeof check. (#308)

Author: 03eltond

packages/shared/sdk-server/src/Migration.ts

@@ -355,7 +355,7 @@ class Migration<
     let end;
     let result: TResult;
     // TODO: Need to validate performance existence check with edge SDKs.
-    if (typeof performance !== undefined) {
+    if (typeof performance !== 'undefined') {
       start = performance.now();
       result = await method();
       end = performance.now();