Changes

Fix lint errors: do not use bare except

src/osmocom/construct.py:90:9: E722 Do not use bare `except`
   |
88 |             ad = GsmString(GreedyBytes)
89 |             return ad._encode(obj, context, path)
90 |         except:
   |         ^^^^^^ E722
91 |             ad = Ucs2Adapter(GreedyBytes)
92 |             return ad._encode(obj, context, path)

Change-Id: Ia5fe852b6d990ad728fc3dedc7012c8fced92e13