fdo#79427 after execute() a ResultSet is expected to be BeforeFirst

Change-Id: I38091d1ee2161d6e32da3a0bde60e3fc008aa83d
Reviewed-on: https://gerrit.libreoffice.org/9794
Reviewed-by: Lionel Elie Mamane <lionel@mamane.lu>
Tested-by: Lionel Elie Mamane <lionel@mamane.lu>