Improve error messages

Author: sharadraju

lib/errors.js

@@ -399,9 +399,9 @@ messages.set(ERR_EXEC_MODE_ONLY_FOR_DML,                // NJS-095
 messages.set(ERR_INVALID_BIND_NAME,                     // NJS-097
   'no bind placeholder named ":%s" was found in the statement text');
 messages.set(ERR_WRONG_NUMBER_OF_BINDS,                 // NJS-098
-  '%s bind placeholders were used in the SQL statement but %s bind values were provided');
+  '%d bind placeholders were used in the SQL statement but %d bind values were provided');
 messages.set(ERR_BUFFER_LENGTH_INSUFFICIENT,            // NJS-099
-  'internal error: buffer of length %s insufficient to hold %s bytes');
+  'internal error: buffer of length %d insufficient to hold %d bytes');
 messages.set(ERR_NCHAR_CS_NOT_SUPPORTED,                // NJS-100
   'national character set id %d is not supported by node-oracledb in Thin mode');
 messages.set(ERR_MISSING_CREDENTIALS,                   // NJS-101