Fixed values passed in to get_combo_xml and get_dtype_combo_xml calls.

Fixed values passed in to get_combo_xml and get_dtype_combo_xml calls methods to rebuild Type and Data Type DhtmlxCombos on schema editor screen.

https://bugzilla.redhat.com/show_bug.cgi?id=1087930
https://bugzilla.redhat.com/show_bug.cgi?id=1109984
Merge pull request #30 from h-kataria/ae_schema_field_delete_fix

Fixed values passed in to get_combo_xml and get_dtype_combo_xml calls.