Remove unused SessionPoolPorts declaration

Author: knizhnik

src/include/miscadmin.h

@@ -164,7 +164,6 @@ extern PGDLLIMPORT int MaxBackends;
 extern PGDLLIMPORT int MaxConnections;
 extern PGDLLIMPORT int MaxSessions;
 extern PGDLLIMPORT int SessionPoolSize;
-extern PGDLLIMPORT int SessionPoolPorts;
 extern PGDLLIMPORT int max_worker_processes;
 extern PGDLLIMPORT int max_parallel_workers;