Remove redundant initialization in clients

the `memset(&cfg, 0, sizeof(struct mosq_config));` already exsits in
`client_config_load()`'s `init_config()` function call.
So calling it in main function is totally unnecessary.

Signed-off-by: YangHau <vulxj0j8j8@gmail.com>

client/pub_client.c

@@ -443,7 +443,6 @@ int main(int argc, char *argv[])
 
 	if(pub_shared_init()) return 1;
 
-	memset(&cfg, 0, sizeof(struct mosq_config));
 	rc = client_config_load(&cfg, CLIENT_PUB, argc, argv);
 	if(rc){
 		if(rc == 2){

client/rr_client.c

@@ -252,8 +252,6 @@ int main(int argc, char *argv[])
 #ifndef WIN32
 		struct sigaction sigact;
 #endif
-	
-	memset(&cfg, 0, sizeof(struct mosq_config));
 
 	mosquitto_lib_init();
 

client/sub_client.c

@@ -278,8 +278,6 @@ int main(int argc, char *argv[])
 #ifndef WIN32
 		struct sigaction sigact;
 #endif
-	
-	memset(&cfg, 0, sizeof(struct mosq_config));
 
 	mosquitto_lib_init();