a minor clarification comment about sqlite3_close()

git-svn-id: svn://bind10.isc.org/svn/bind10/trunk@1180 e5f2f494-b856-4b98-b285-d166d9295462

src/lib/auth/data_source_sqlite3.cc

@@ -687,6 +687,7 @@ Sqlite3DataSrc::open(const string& name) {
     
     if (sqlite3_open(database_name.c_str(), &db) != 0) {
         cerr << "open database: " << sqlite3_errmsg(db) << "\n";
+        // sqlite3_close() must be called even when open fails.
         sqlite3_close(db);
         throw("Cannot open database");
     }