fix(mcp): use boolean credsChanged, not the imported function ref

shouldClearCache was checking the always-truthy oauthCredsChanged function
import instead of the awaited boolean, so PATCH always cleared the cache.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: waleedlatif1

apps/sim/app/api/mcp/servers/[id]/route.ts

@@ -186,7 +186,7 @@ export const PATCH = withRouteHandler(
 
         const shouldClearCache =
           urlChanged ||
-          oauthCredsChanged ||
+          credsChanged ||
           body.enabled !== undefined ||
           body.headers !== undefined ||
           body.timeout !== undefined ||