tz-erl: Fix offset_minutes($o) when $o just digits is hours offset.
tz-erl: Fix offset_minutes($o) when $o just digits is hours offset.

Previouly when offset_minute's argument was just digits (for example,
"+2" instead of "+2:00"), the argument was incorrectly interpreted as
minutes when it should be as hours.

choptastic/erlang_localtime