Fix import error

src/fastmcp/server/http.py

@@ -22,10 +22,11 @@ from starlette.responses import Response
 from starlette.routing import Mount, Route
 from starlette.types import Receive, Scope, Send
 
-# This import is vendored until it is finalized in the upstream SDK
-from fastmcp.server.streamable_http_manager import StreamableHTTPSessionManager
 from fastmcp.utilities.logging import get_logger
 
+# This import is vendored until it is finalized in the upstream SDK
+from fastmcp.vendor.streamable_http_manager import StreamableHTTPSessionManager
+
 if TYPE_CHECKING:
     from fastmcp.server.server import FastMCP