Misc bug fixes

Bug fixes

bug: Correction needed because "%z" gives you timezone offset without colon. bug: flask 2.2.2 install latest version of Werkzeug, but does not support Werkzeug v3. solution is to specify Werkzeug to 2.3.6 in requirements bug: for dataflow G, numberExceedance must be int not float bug: allow assessment regime to have no zone from gui