db_text(k): init new db text table structure to 0

kamailio git 1425fb2408b13d82528868dc1ad6e97639f7439f
db_text(k): init new db text table structure to 0

- can cause a crash when reloading, reported by Bruno Bresciani
(cherry picked from commit c54b89a3a840e032a2a8abc5842b3ea78fa537ba)

modules_k/db_text/dbt_tb.c

@@ -149,6 +149,7 @@ dbt_table_p dbt_table_new(const str *_tbname, const str *_dbname, const char *pa
 	dtp = (dbt_table_p)shm_malloc(sizeof(dbt_table_t));
 	if(!dtp)
 		goto done;
+	memset(dtp, 0, sizeof(dbt_table_t));
 	dtp->name.s = (char*)shm_malloc((_tbname->len+1)*sizeof(char));
 	if(!dtp->name.s)
 	{