Blitz saveDefaults() doesn't use 'omero.user'. Reverts 7c236f6. Fixes…

… #8814

Also we use canAnnotate() to test whether we can save settings, since they are annotations on the image.

components/tools/OmeroPy/src/omero/gateway/__init__.py

@@ -7027,7 +7027,7 @@ def saveDefaults (self):
         @return: Boolean
         """
 
-        if not self.isEditable():
+        if not self.canAnnotate():
             return False
         ns = self._conn.CONFIG.get('IMG_ROPTSNS', None)
         if ns:
@@ -7039,7 +7039,6 @@ def saveDefaults (self):
             self.linkAnnotation(ann)
         sopts = dict(self._conn.CONFIG['SERVICE_OPTS'] or {})
         sopts['omero.group'] = str(self.getDetails().getGroup().getId())
-        sopts['omero.user'] = str(self.getDetails().getOwner().getId())
         self._re.saveCurrentSettings(sopts)
         return True