Update postgres_asio.h

Author: skarlsson

postgres_asio/postgres_asio.h

@@ -11,8 +11,12 @@
 #endif
 
 #ifdef __LINUX__
+#if __LSB_DISTRIBUTOR_ID__ == "centos"
+#include <libpq-fe.h>
+#else
 #include <postgresql/libpq-fe.h>
 #endif
+#endif
 
 //inspiration
 //https://github.com/brianc/node-libpq