Compile PlatON warning in function check_platon_wallet

[PanHH]

Describe the bug
Compile PlatON warning in function check_platon_wallet

01Wallet.c: In function 'check_platon_wallet':
01Wallet.c:28:22: warning: pointer targets in passing argument 1 of 'strncmp' differ in signedness [-Wpointer-sign]
     result = strncmp(wallet_ptr->account_info.prikeyCtx.extra_data.value, platon_private_key_buf, strlen(platon_private_key_buf));
                      ^~~~~~~~~~
In file included from /usr/include/check.h:26:0,
                 from tcase_platon.h:20,
                 from 01Wallet.c:16:
/usr/include/string.h:139:12: note: expected 'const char *' but argument is of type 'BUINT8 * {aka unsigned char *}'
 extern int strncmp (const char *__s1, const char *__s2, size_t __n)
            ^~~~~~~