Fixed few anomalies detected with valgrind

lib/MySQL_Thread.cpp

@@ -1977,9 +1977,9 @@ void MySQL_Threads_Handler::init(unsigned int num, size_t stack) {
 	}
 	int rc=pthread_attr_setstacksize(&attr, stacksize);
 	assert(rc==0);
-	mysql_threads=(proxysql_mysql_thread_t *)malloc(sizeof(proxysql_mysql_thread_t)*num_threads);
+	mysql_threads=(proxysql_mysql_thread_t *)calloc(num_threads,sizeof(proxysql_mysql_thread_t));
 #ifdef IDLE_THREADS
-	mysql_threads_idles=(proxysql_mysql_thread_t *)malloc(sizeof(proxysql_mysql_thread_t)*num_threads);
+	mysql_threads_idles=(proxysql_mysql_thread_t *)calloc(num_threads,sizeof(proxysql_mysql_thread_t));
 #endif // IDLE_THREADS
 }
 

lib/mysql_connection.cpp

@@ -196,6 +196,9 @@ MySQL_Connection::~MySQL_Connection() {
 		delete userinfo;
 		userinfo=NULL;
 	}
+	if (local_stmts) {
+		delete local_stmts;
+	}
 	if (mysql) {
 		// always decrease the counter
 		if (ret_mysql)
@@ -207,9 +210,6 @@ MySQL_Connection::~MySQL_Connection() {
 	if (MyRS) {
 		delete MyRS;
 	}
-	if (local_stmts) {
-		delete local_stmts;
-	}
 	if (query.stmt) {
 		query.stmt=NULL;
 	}