[erp5_officejs_connector] Use format rfc822 dates in form

To be consistant with date format in hateoas
And follow Javascript default format
https://developer.mozilla.org/fr/docs/Web/JavaScript/Reference/Objets_globaux/Date/parse

bt5/erp5_officejs_connector/SkinTemplateItem/portal_skins/erp5_officejs_jio_connector.xml

@@ -6,6 +6,12 @@
     </pickle>
     <pickle>
       <dictionary>
+        <item>
+            <key> <string>_local_properties</string> </key>
+            <value>
+              <tuple/>
+            </value>
+        </item>
         <item>
             <key> <string>_objects</string> </key>
             <value>

bt5/erp5_officejs_connector/SkinTemplateItem/portal_skins/erp5_officejs_jio_connector/File_viewAsJIO/your_modification_date.xml

@@ -279,7 +279,7 @@
       <dictionary>
         <item>
             <key> <string>_text</string> </key>
-            <value> <string>python: here.getModificationDate().HTML4()</string> </value>
+            <value> <string>python: here.getModificationDate().rfc822()</string> </value>
         </item>
       </dictionary>
     </pickle>

bt5/erp5_officejs_connector/SkinTemplateItem/portal_skins/erp5_officejs_jio_connector/OOoDocument_viewAsJio/your_modification_date.xml

@@ -279,7 +279,7 @@
       <dictionary>
         <item>
             <key> <string>_text</string> </key>
-            <value> <string>python: here.getModificationDate().HTML4()</string> </value>
+            <value> <string>python: here.getModificationDate().rfc822()</string> </value>
         </item>
       </dictionary>
     </pickle>

bt5/erp5_officejs_connector/SkinTemplateItem/portal_skins/erp5_officejs_jio_connector/OOoDocument_viewAsJioWithData/your_modification_date.xml

@@ -279,7 +279,7 @@
       <dictionary>
         <item>
             <key> <string>_text</string> </key>
-            <value> <string>python: here.getModificationDate().HTML4()</string> </value>
+            <value> <string>python: here.getModificationDate().rfc822()</string> </value>
         </item>
       </dictionary>
     </pickle>

bt5/erp5_officejs_connector/SkinTemplateItem/portal_skins/erp5_officejs_jio_connector/WebPage_viewAsJio/your_modification_date.xml

@@ -279,7 +279,7 @@
       <dictionary>
         <item>
             <key> <string>_text</string> </key>
-            <value> <string>python: here.getModificationDate().HTML4()</string> </value>
+            <value> <string>python: here.getModificationDate().rfc822()</string> </value>
         </item>
       </dictionary>
     </pickle>