Restore definition of slurm_get_track_wckey() that was accidentally removed

src/common/slurm_protocol_api.h

@@ -286,11 +286,10 @@ extern char *slurm_get_crypto_type(void);
  */
 extern uint16_t slurm_get_fast_schedule(void);
 
-/* slurm_get_crypto_type
- * returns the crypto_type from slurmctld_conf object
- * RET char *    - crypto type, MUST be xfreed by caller
+/* slurm_get_track_wckey
+ * returns the value of track_wckey in slurmctld_conf object
  */
-extern char *slurm_get_crypto_type(void);
+extern uint16_t slurm_get_track_wckey(void);
 
 /* slurm_get_topology_plugin
  * returns the value of topology_plugin in slurmctld_conf object