Fix testSurchargeWithInvalidDateTime

This reverts parts of 3b22ae1f
As the field has default_to_now set, if we save "" it will display now

bt5/erp5_ui_test/PathTemplateItem/portal_tests/datetime_field_zuite/testSurchargeWithInvalidDateTime.xml

@@ -179,31 +179,6 @@
   <td>//button[@title=\'Save\']</td>\n
   <td></td>\n
 </tr>\n
-<tr>\n
-  <td>verifyValue</td>\n
-  <td>subfield_field_my_start_date_year</td>\n
-  <td></td>\n
-</tr>\n
-<tr>\n
-  <td>verifyValue</td>\n
-  <td>subfield_field_my_start_date_month</td>\n
-  <td></td>\n
-</tr>\n
-<tr>\n
-  <td>verifyValue</td>\n
-  <td>subfield_field_my_start_date_day</td>\n
-  <td></td>\n
-</tr>\n
-<tr>\n
-  <td>verifyValue</td>\n
-  <td>subfield_field_my_start_date_hour</td>\n
-  <td></td>\n
-</tr>\n
-<tr>\n
-  <td>verifyValue</td>\n
-  <td>subfield_field_my_start_date_minute</td>\n
-  <td></td>\n
-</tr>\n
 <tr>\n
   <td>assertTextNotPresent</td>\n
   <td>You did not enter a valid date and time.</td>\n

bt5/erp5_ui_test/bt/revision

-706
\ No newline at end of file
+707
\ No newline at end of file