Fix crash when multiple MySQL monitors monitor same servers

The monitors always freed and reallocated the memory for the slaves. It
was always of the same size so a static array of that size should also
work.

server/core/server.c

@@ -81,7 +81,6 @@ server_alloc(char *servname, char *protocol, unsigned short port)
     server->rlag = -2;
     server->master_id = -1;
     server->depth = -1;
-    server->slaves = NULL;
     server->parameters = NULL;
     server->server_string = NULL;
     spinlock_init(&server->lock);