Update code comment

Author: cjbj

lib/oracledb.js

@@ -234,7 +234,7 @@ async function createPool(poolAttrs) {
 
 //-----------------------------------------------------------------------------
 // getConnection()
-//   Gets a standalone connection from the database.
+//   Gets either a standalone connection, or a connection from a pool cache
 //-----------------------------------------------------------------------------
 async function getConnection(a1) {
   let pool;