Fix csp error in frontend when forcing offline. (Comfy-Org#11749)

Author: comfyanonymous

server.py

@@ -184,7 +184,7 @@ async def block_external_middleware(request: web.Request, handler):
         else:
             response = await handler(request)
 
-        response.headers['Content-Security-Policy'] = "default-src 'self'; script-src 'self' 'unsafe-inline' 'unsafe-eval' blob:; style-src 'self' 'unsafe-inline'; img-src 'self' data: blob:; font-src 'self'; connect-src 'self'; frame-src 'self'; object-src 'self';"
+        response.headers['Content-Security-Policy'] = "default-src 'self'; script-src 'self' 'unsafe-inline' 'unsafe-eval' blob:; style-src 'self' 'unsafe-inline'; img-src 'self' data: blob:; font-src 'self'; connect-src 'self' data:; frame-src 'self'; object-src 'self';"
         return response
 
     return block_external_middleware