fix dnspod error: Communication with checkip server %s failed

[V-E-O]

The plugin of dnspod had server_url = "". When I configured check_ip_server, the "get address from remote" function in ddns.c gets always returned.
static int get_address_remote(ddns_t *ctx, ddns_info_t *info, char *address, size_t len) { if (!info->server_url[0]) return 1;

The easy fix is change empty string to "/" in dnspod plugin.
Well, I believe another fix to the IF-condition "if (!info->server_url[0])" should be done. Maybe some plugin has empty server_url but always has server_name.
static ddns_system_t plugin = { .server_name = "dnsapi.cn", .server_url = "" };
Like as

- if (!info->server_url[0])
+ if (!info->server_name[0])

[troglobit]

Appreciate the analysis, I think you are spot on. Would you mind redoing the PR with your suggested change to:

inadyn/src/ddns.c

Lines 335 to 339 in 2a99888

	static int get_address_remote(ddns_t *ctx, ddns_info_t *info, char *address, size_t len)
	{
	if (!info->server_url[0])
	return 1;

[V-E-O]

Hi, I modified the condition from check ddns provider api server to checkip server name.