Further simplify code

lib/nexrad/afos.py

@@ -3,8 +3,6 @@ import enum
 import datetime
 import shapely
 
-from typing import Self
-
 from nexrad.db    import DatabaseTable
 from nexrad.coord import COORD_SYSTEM
 from nexrad.vtec  import VTECEvent
@@ -220,11 +218,16 @@ class AFOSMessageParser():
     def parse_body(self, line: str):
         if line == '&&':
             self.state = AFOSMessageParserState.TAGS
-        elif self.timestamp is None:
+            return
+
+        if self.timestamp is not None:
+            return
+
         match = RE_DATE.match(line)
 
         if match is not None:
             tzoffset = TIMEZONES[match['tz'].upper()]
+            tzinfo   = datetime.timezone(datetime.timedelta(hours=tzoffset))
 
             self.timestamp = datetime.datetime(
                 year   = int(match['year']),
@@ -233,7 +236,7 @@ class AFOSMessageParser():
                 hour   = int(match['hour']),
                 minute = int(match['minute']),
                 second = 0,
-                    tzinfo = datetime.timezone(datetime.timedelta(hours=tzoffset))
+                tzinfo = tzinfo
             ).astimezone(datetime.UTC)
 
     def parse_tags(self, line: str):