Add function prototype to remove warning

Author: michael-grunder

redis_commands.h

@@ -145,6 +145,9 @@ int redis_hmget_cmd(INTERNAL_FUNCTION_PARAMETERS, RedisSock *redis_sock,
 int redis_hmset_cmd(INTERNAL_FUNCTION_PARAMETERS, RedisSock *redis_sock,
     char **cmd, int *cmd_len, short *slot, void **ctx);
 
+int redis_hstrlen_cmd(INTERNAL_FUNCTION_PARAMETERS, RedisSock *redis_sock,
+    char **cmd, int *cmd_len, short *slot, void **ctx);
+
 int redis_bitop_cmd(INTERNAL_FUNCTION_PARAMETERS, RedisSock *redis_sock, 
     char **cmd, int *cmd_len, short *slot, void **ctx);